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Design of 3D-printed Cable Driven Humanoid Hand Based on Bidirectional Elastomeric Passive Transmission

Chinese Journal of Mechanical Engineering 2021年第4期34卷 225-235页

作者： Teru Chen Xingwei Zhao Guocai Ma Bo Tao Zhouping Yin State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System EngineeringBeijing 100854China

Motion control of the human hand is the most complex part of the human *** has always been a challenge for a good balance between the cost,weight,responding speed,grasping force,finger extension,and dexterity of prosthetic *** solve these issues,a 3D-printed cable driven humanoid hand based on bidirectional elastomeric passive transmission(BEPT)is designed in this paper.A semi-static model of BEPT is investigated based on energy conservation law to analyze the mechanical properties of BEPT and a dynamical simulation of finger grasping is *** a good imitation of human hand and an excellent grasping performance,specific BEPT is selected according to human finger grasping *** advantage of BEPT based humanoid hand is that a good balance between the price and performance of the humanoid hand is *** proved that the designed prosthetic hand’s single fingertip force can reach 33 N and the fastest fingertip grasping speed realized 0.6 s/180°.It also has a good force compliance effect with only 430g’s *** can not only grab fragile objects like raw eggs and paper cup,but also achieve strong grasping force to damage metal *** humanoid hand has considerable application prospects in artificial prosthesis,human-computer interaction,and robot operation.

关键词： Humanoid hand Bidirectional elastomeric passive transmission Artificial prosthesis

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An Unbalance Identification Method of a Whole Aero-Engine Based on the Casing Vibrations 11th

An Unbalance Identification Method of a Whole Aero-Engine Ba...

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11th IFToMM International Conference on Rotordynamics, IFToMM 2023

作者： Wang, Weimin Wang, Jiale Li, Qihang Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Mechanical Equipment Beijing University of Chemical Technology Beijing100029 China State Key Laboratory of High-End Compressor and System Technology Beijing China

ISBN: (纸本)9783031404580

Squeeze film dampers (SFDs) have been frequently employed in aero-engines due to their excellent vibration reduction performance. However, their nonlinear characteristics make it difficult for traditional balancing methods to achieve efficient vibration suppression. In addition, because of the harsh condition and restricted space inside the casing, sensors are only able to be installed on the surface of the casing to evaluate the operational state of an aero-engine. Therefore, it is vital to propose an unbalance identification method of a whole aero-engine with SFDs. In this paper, the equivalent unbalance calculation equation, which takes the vibration transfer characteristics of the casing, nonlinear oil film forces, the flexible support and gyroscopic moments into account, is derived by decoupling the differential equation of rotor motion in modal coordinates. The equivalent unbalance distribution of the rotor is generated by solving very ill-conditioned linear equations produced by modal parameters. Finally, a nonlinear unbalance identification method based on casing vibrations is developed. By establishing a whole aero-engine dynamics model, simulation is used to verify the accuracy of this unbalance identification method. The results show that, when the High Pressure rotor has unbalance alone, the vibration reduction rates for the aero-engine rotor system are no less than 93%. For the condition that HP and LP rotors are unbalanced at the same time, using the excitation source separation method proposed in this paper, the balancing effects are also very significant. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Nonlinear equations

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A Genderless Docking Mechanism with Passive Locking and High Rotation Misalignment Tolerance for Modular Space Robots

A Genderless Docking Mechanism with Passive Locking and High...

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2022 IEEE International Conference on robotics and Biomimetics, ROBIO 2022

作者： Chen, Jian Wen, Xiaodong Wang, Hao Gong, Wei Deng, Zongquan Yu, Haitao Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin Key Laboratory of Aerospace Intelligent Equipment Technology Tianjin China

ISBN: (纸本)9781665481090

Modular robots are gaining increasing attention in space services. The docking mechanism plays a critical role in performing self-healing and self-reconfiguration of modular robots. It is beneficial for the docking mechanism to operate with high efficiency, homogeneity and high misalignment tolerances. To meet these requirements, this paper presents a novel genderless docking mechanism. The construction of the docking mechanism is designed with features of passive locking and single-sided electromagnetic unlocking. To demonstrate the advantages of passive locking, the working processes of the axial and circumferential locking mechanisms are described in detail. Based on theoretical calculations and simulations, it is shown that the docking mechanism can provide fast connections or disconnections with a degree of translational and angular misalignment tolerances. This docking mechanism is intended for future applications in modular space robots or unstructured environment exploration robots. © 2022 IEEE.

关键词： Modular robots

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Investigation on influence of gamma irradiation on piezoelectric and resonance characteristics of surface acoustic wave resonators 5

Investigation on influence of gamma irradiation on piezoelec...

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5th International Conference on Mechanical Engineering and Materials, ICMEM 2024

作者： Sun, Lei Peng, Bin Yang, Yuntao Sun, Zhaofeng Zhu, Jialiang Zhang, Wanli State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (数字)9781510688971

ISBN: (纸本)9781510688964

In this work, an evaluation towards influence of high-dose gamma irradiation on surface acoustic wave (SAW) resonators, is reported. The single-port SAW resonators are fabricated using Lithium niobate (LiNbO3) and Catangasite (CTGS, Ca3TaGa3Si2O14) substrates, along respective cut directions of (0º, 38º, 0º) and (0º, 90º, 0º). Piezoelectric coefficient of substrates, and several main resonance parameters covering resonance frequency, amplitude of resonance peak in reflection coefficient, quality factor together with electromechanical coupling factor of manufactured SAW resonators are investigated, as suitable representatives of piezoelectric and resonance characteristics of SAW resonators. After exposure to gamma ray with a maximum dose of 250 kGy, substrates show insignificant variation not exceeding 6% in their piezoelectric coefficient. Meanwhile, resonance parameters of SAW resonators also alter slightly. Such excellent stability of these characteristics demonstrates credible irradiation hardness owned by both SAW resonators. Results in this study can provide supportive references for usage of LiNbO3 and CTGS-based SAW devices in harsh environments. © 2025 SPIE.

关键词： Gamma rays

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Design and Performance Analysis of HMDV Dynamic Inertial Suspension Based on Active Disturbance Rejection Control

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1485-1506页

作者： Xiaofeng Yang Wei Wang Yujie Shen Changning Liu Tianyi Zhang School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China Automotive Engineering Research Institute Jiangsu UniversityZhenjiang212013China Chongqing Key Laboratory of Urban Rail Transit System Integration and Control Chongqing400074China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan universityChangsha410082China

This paper addresses the impact of vertical vibration negative effects,unbalanced radial forces generated by the static eccentricity of the hub motor,and road excitation on the suspension performance of Hub Motor Driven Vehicle(HMDV).A dynamic inertial suspension based on Active Disturbance Rejection Control(ADRC)is proposed,combining the vertical dynamic characteristics of dynamic inertial suspension with the features of ADRC,which distinguishes between internal and external disturbances and arranges the transition ***,a simulation model of the static eccentricity of the hub motor is established to simulate the unbalanced radial electromagnetic force generated under static eccentricity.A quarter-vehicle model of an HMDV with a controllable dynamic inertial suspension is then ***,the passive suspension model is studied under different grades of road excitation,and the impact mechanism of suspension performance at speeds of 0–20 m/s is ***,the three main components within the ADRC controller are designed for the second-order controlled system,and optimization algorithms are used to optimize its internal ***,the performance of the traditional passive suspension,the PID-based controllable dynamic inertial suspension,and the ADRC-based controllable dynamic inertial suspension are analyzed under different road *** results show that,under sinusoidal road input,the ADRC-based controllable dynamic inertial suspension exhibits a 52.3%reduction in the low-frequency resonance peak in the vehicle body acceleration gain diagram compared to the traditional passive suspension,with significant performance optimization in the high-frequency *** random road input,the ADRC-based controllable dynamic inertial suspension achieves a 29.53%reduction in the root mean square value of vehicle body acceleration and a 14.87%reduction in dynamic tire *** indicates that the designed controllable dynamic inertia

关键词： HMDV static eccentricity ADRC dynamic inertial suspension road excitation

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A Cost-Sensitive Multi-scale Feature Multi-order Fusion Network for Bearing Fault Diagnosis Under Data Imbalance Conditions

A Cost-Sensitive Multi-scale Feature Multi-order Fusion Netw...

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International Conference on Artificial Intelligence and Autonomous Transportation, AIAT 2024

作者： Deng, Shuaiqing Lei, Zihao Wen, Guangrui Su, Yu Liu, Zimin Meng, Zhangxuan Zhang, Zhifen National Key Laboratory of Aviation Power System and Plasma Technology Xi’an Jiaotong University Xi’an710049 China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an710049 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong University Xi’an710049 China

ISBN: (纸本)9789819639724

Railroad transportation plays a vital role in the national economy, and fault diagnosis of its key components is of great significance in ensuring its safe operation. However, due to its long-term operation in a healthy state, it is tough to obtain fault signals, and this class imbalance data seriously degrades the diagnostic capability of intelligent diagnostic algorithms, leading to increased misclassification of minority classes. To address this problem, we propose a cost-sensitive multi-scale feature multi-order fusion network for bearing fault diagnosis under data imbalance conditions. Firstly, a lightweight multi-scale convolutional layer is employed to effectively extract the multi-scale features of the signal. Then the multi-order feature fusion is performed by a hornet to fully utilize the multi-scale information and enhance the ability to mine the limited diagnostic information of the minority class. And the excellent high-dimensional discriminative features are extracted through residual blocks. In addition, an improved cost-sensitive strategy is designed through the posterior probability distribution to rebalance the contribution of each class to the training process for improving the overall diagnostic performance of the model. Finally, the effectiveness and superiority of the proposed method are comprehensively verified by several sets of experiments with different imbalance rates. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Railroad transportation

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Cavitation recognition of axial piston pumps in noisy environment based on Grad-CAM visualization technique

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CAAI Transactions on Intelligence technology 2023年第1期8卷 206-218页

作者： Qun Chao Xiaoliang Wei Jianfeng Tao Chengliang Liu Yuanhang Wang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghaiChina State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhouChina MoE Key Laboratory of Artificial Intelligence AI InstituteShanghai Jiao Tong UniversityShanghaiChina China Electronic Product Reliability and Environmental Testing Research Institute GuangzhouChina Guangdong Provincial Key Laboratory of Electronic Information Products Reliability Technology GuangzhouChina

The cavitation in axial piston pumps threatens the reliability and safety of the overall hydraulic *** signal can reflect the cavitation conditions in axial piston pumps and it has been combined with machine learning to detect the pump ***,the vibration signal usually contains noise in real working conditions,which raises concerns about accurate recognition of cavitation in noisy *** paper presents an intelligent method to recognise the cavitation in axial piston pumps in noisy ***,we train a convolutional neural network(CNN)using the spectrogram images transformed from raw vibration data under different cavitation ***,we employ the technique of gradient-weighted class activation mapping(Grad-CAM)to visualise class-discriminative regions in the spectrogram ***,we propose a novel image processing method based on Grad-CAM heatmap to automatically remove entrained noise and enhance class features in the spectrogram *** experimental results show that the proposed method greatly improves the diagnostic performance of the CNN model in noisy *** classification accuracy of cavitation conditions increases from 0.50 to 0.89 and from 0.80 to 0.92 at signal-to-noise ratios of 4 and 6 dB,respectively.

关键词： axial piston pump cavitation recognition CNN Grad-CAM spectrogram image

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Late sowing enhances lodging resistance of wheat plants by improving the biosynthesis and accumulation of lignin and cellulose

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Journal of Integrative Agriculture 2023年第5期22卷 1351-1365页

作者： DONG Xiu-chun QIAN Tai-feng CHU Jin-peng ZHANG Xiu LIU Yun-jing DAI Xing-long HE Ming-rong State Key Laboratory of Crop Biology Ministry of Science and Technology/Key Laboratory of Crop Ecophysiology and Farming SystemMinistry of Agriculture and Rural Affairs/Agronomy CollegeShandong Agricultural UniversityTai’an 271018P.R.China Jining Agricultural Technology Extension Center Jining 272113P.R.China

Delayed sowing mitigates lodging in wheat. However, the mechanism underlying the enhanced lodging resistance in wheat has yet to be fully elucidated. Field experiments were conducted to investigate the effects of sowing date on lignin and cellulose metabolism, stem morphological characteristics, lodging resistance, and grain yield. Seeds of Tainong 18,a winter wheat variety, were sown on October 8(normal sowing) and October 22(late sowing) during both of the 2015–2016 and 2016–2017 growing seasons. The results showed that late sowing enhanced the lodging resistance of wheat by improving the biosynthesis and accumulation of lignin and cellulose. Under late sowing, the expression levels of key genes(Ta PAL, Ta CCR, Ta COMT, TaCAD, and TaCesA1, 3, 4, 7, and 8) and enzyme activities(TaPAL and TaCAD) related to lignin and cellulose biosynthesis peaked 4–12 days earlier, and except for the TaPAL, TaCCR, and TaCesA1 genes and TaPAL, in most cases they were significantly higher than under normal sowing. As a result, lignin and cellulose accumulated quickly during the stem elongation stage. The mean and maximum accumulation rates of lignin and cellulose increased, the maximum accumulation contents of lignin and cellulose were higher, and the cellulose accumulation duration was prolonged. Consequently, the lignin/cellulose ratio and lignin content were increased from 0 day and the cellulose content was increased from 11 days after jointing onward. Our main finding is that the improved biosynthesis and accumulation of lignin and cellulose were responsible for increasing the stem-filling degree, breaking strength, and lodging resistance. The major functional genes enhancing lodging resistance in wheat that are induced by delayed sowing need to be determined.

关键词： cellulose late sowing lignin lodging resistance wheat

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Loaded tooth contact analysis and meshing stiffness calculation for cracked spiral bevel gears

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Chinese Journal of Aeronautics 2025年第3期38卷 593-623页

作者： Zhen LIU Fucai LI Wenjie BAO Xiaolei XU Freeda A.AMIR State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China Jiangsu JITRI Composite Equipment Research Institute Co. Ltd.Wuxi 214000China

Tooth cracks may occur in spiral bevel gear transmission system of the aerospace *** this study,an accurate and efficient loaded tooth contact analysis(LTCA)model is developed to predict the contact behavior and time-varying meshing stiffness(TVMS)of spiral bevel gear pair with cracked *** tooth is sliced,and the contact points on slices are computed using roll angle *** the geometric complexity of crack surface,a set of procedures is formulated to generate spatial crack and determine crack parameters for contact *** to the positional relationship between contact point and crack path,each sliced tooth is modeled as a non-uniform cantilever beam with varying reduced effective load-bearing tooth *** the compliance model of the cracked tooth is established to perform contact analysis,along with TVMS calculations utilizing three different *** employing spiral bevel gear pairs with distinct types of cracks as examples,the accuracy and efficiency of the developed approach are validated via comparative analyses with finite element analysis(FEA)***,the investigation on effects of cracks shows that tooth cracks can induce alterations in meshing performance of both entire gear pair and individual tooth pairs,including not only cracked tooth pair but also adjacent non-cracked tooth ***,the proposed model can serve as a useful tool for analyzing the variations in contact behavior and meshing stiffness of spiral bevel gears due to different cracks.

关键词： Bevel gears Gear teeth Cracks Loaded tooth contact analysis Time-varying meshing stiffness Tooth compliance

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Decomposing Visual and Semantic Correlations for Both Fully Supervised and Few-Shot Image Classification

IEEE Transactions on Artificial Intelligence

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IEEE Transactions on Artificial Intelligence 2024年第4期5卷 1658-1668页

作者： Zhang, Chunjie Zheng, Xiaolong Beijing Jiaotong University Institute of Information Science Beijing100044 China Beijing Jiaotong University Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing100044 China University of Chinese Academy of Sciences State Key Laboratory of Multimodal Artificial Intelligence Systems The State of Key Laboratory of Management and Control for Complex System Institute of Automation Chinese Academy of Sciences School of Artificial Intelligence Beijing100190 China

Most image classification methods are designed to either boost the classification accuracies with abundant supervision, or cope with the shortage of supervision information. This is often achieved by using the visual and semantic information of other sources. However, these methods use the visual and semantic information within the same class independently, leaving their intrinsic correlations unconsidered. Objects and disturbing components as well as noise exist on the same image. Besides, semantic representations also contain noisy information. To solve the problems mentioned above, we propose a novel method for both fully supervised image classification and few-shot image classification by decomposing visual and semantic correlations. We jointly explore the intrinsic correlations of visual and semantic information of images within the same class. For each class, we decompose its visual and semantic correlations using low-rank and sparse constraint respectively. The decomposed low-rank parts character the intrinsic correlations of images can be used in a linear transformation way. Using the decomposed parts of each class, Classification can be achieved by reconstruction error minimization. We conduct experiments on several datasets for both fully supervised image classification and few-shot image classification. Experimental results well show the effectiveness of the proposed method. © 2020 IEEE.

关键词： Semantics

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