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Mechanical design,modeling,and identification for a novel antagonistic variable stiffness dexterous finger

Frontiers of Mechanical Engineering 2022年第3期17卷 59-74页

作者： Handong HU Yiwei LIU Zongwu XIE Jianfeng YAO Hong LIU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments,such as unstructured or man-made operational errors through comprehensive consideration of cost,accuracy,manufacturing,and *** on the concept of mechanical passive compliance,which is widely implemented in robots for interactions,a finger is dedicated to improving mechanical *** finger mechanism not only achieves passive compliance against physical impacts,but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory *** achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust *** mechanical design of the finger and its stiffness adjusting methods are *** stiffness characteristics of the finger joint and the actuation unit are *** results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the *** have been experimentally proven to be robust against physical ***,the experimental part verifies that fingers have good power,grasping,and manipulation performance.

关键词： multifingered hand mechanism design robot safety variable stiffness actuator

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The deleterious effects and potential therapeutic strategy of fluorene-9-bisphenol on circadian activity and liver diseases in zebrafish and mice

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Journal of Environmental Sciences 2024年第11期145卷 13-27页

作者： Shuhui Zhang Xiang Zuo Jialu Luan Huijuan Bai Zhenhua Fu Mingzhu Sun Xin Zhao Xizeng Feng College of Life Science State Key Laboratory of Medicinal Chemical BiologyThe Key Laboratory of Bioactive MaterialsMinistry of EducationNankai UniversityTianjin 300071China Institute of Robotics&Automatic Information System College of Artificial IntelligenceNankai UniversityTianjin 300071China

Increasing evidence indicates that disturbance of the clock genes,which leads to systemic endocrine perturbation,plays a crucial role in the pathogenesis of metabolic and liver ***-9-bisphenol(BHPF)is utilized in the manufacturing of plastic materials but its biological effects on liver homeostasis remain *** impacts and involved mechanisms of BHPF on the liver diseases,metabolism,and circadian clock were comprehensively studied by zebrafish andmouse *** therapeutic effect of melatonin(MT)was also *** and mousemodels with either acute exposure(0.5 and 1μmol/L,1-4 days post-fertilization)or chronic oral exposure(0.5 and 50 mg/(kg·2 days),30 days)were established with various BHPF ***,we identified a crucial role for estrogenic regulation in liver development and circadian locomotor rhythms damaged by BHPF in a zebrafish *** mice showed chaos in circadian activity through the imbalance of circadian clock component Brain and Muscle Aryl hydrocarbon receptor nuclear translocator-like 1 in the liver and *** liver sexual dimorphic alteration alongwith reduced growth hormone and estrogens played a critical role in damaged glucose metabolism,hepatic inflammation,and fibrosis induced by ***,sleep improvement by exogenous MT alleviated BHPF-related glucose metabolism and liver injury in *** proposed the pathogenesis of metabolic and liver disease resulting from BHPF and promising targeted therapy for livermetabolism disorders associated with endocrine perturbation *** results might play a warning role in the administration of endocrine-disrupting chemicals in everyday life and various industry applications.

关键词： Fluorene-9-bisphenol(BHPF) Melatonin Circadian activity Endocrine perturbation Liver diseases Female behavior Hepatic sexual dimorphism

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Hybrid Robotic Arm for Autonomous Aerial Refueling

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Chinese Journal of Mechanical Engineering 2024年第6期37卷 429-440页

作者： Kaixuan Li Gangfeng Liu Yongsheng Gao Jie Zhao State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150080China School of Mechatronics Engineering Harbin 150080China

Autonomous aerial refueling technology is gaining increasing attention to enhance aircraft combat *** research on autonomous refueling focuses mainly on flight control laws,with little attention to the automation of refueling *** leads to high demands on control law performance and navigation accuracy,making it difficult to ensure *** address this,we propose a robotic arm system capable of automatic docking during the flexible aerial refueling *** system uses a conical kinematic space configuration,offering enhanced stability and impact *** frame-type structure achieves a lightweight ***,we establish a single-objective optimization model for the connecting rod dimensions and apply a genetic algorithm(GA)for their *** also propose a trajectory-fitting calibration theory based on the robotic arm's special configuration and complete its movement accuracy calibration using a laser *** calibration method reduces the robotic arm's motion error by 71%,achieving an absolute positioning accuracy better than 3.5 mm,which meets the requirements for autonomous aerial *** summary,this research presents a hybrid robotic arm that meets automatic docking requirements,offering a new approach to autonomous aerial refueling.

关键词： Autonomous aerial refueling Conical kinematic space configuration Optimization of structural design Calibration method

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JHT-EXO: A Soft Ankle Exosuit for Assisting Walking in Patients with Post-Stroke Foot Inversion

JHT-EXO: A Soft Ankle Exosuit for Assisting Walking in Patie...

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2024 IEEE International Conference on robotics and Biomimetics, ROBIO 2024

作者： Ju, Haotian Guan, Zihang Guo, Songhao Liu, Zedong Zhang, Qinghua Zheng, Tianjiao Zhao, Jie Zhu, Yanhe Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9781665481090

Stroke often leads to foot inversion, seriously affecting the patients' walking ability. In this paper, a lightweight, soft exosuit, JHT-EXO, is proposed for correcting foot inversion to help patients' gait rehabilitation. JHT-EXO mainly consists of two cable driving modules, two foot feedback modules, and a control module, with a total weight of no more than 2.5 kg. The cable driving module can pre-tighten the cable with a designed constant torque spring to prevent the cable from falling off. When the motor is not energized, it can still assist the person in stabilizing the walking gait and reducing power consumption. Customized foot pressure sensors recognize human gait, and IMUs on the feet measure the ankle angle used by the controller to change the output force of the exosuit. The constant torque spring was calibrated and tested, and the experimental results showed that the average output force of the constant torque spring was 20.0 N, with a maximum error of 5.6% compared to the theoretically calculated results. The ground walking test of the exosuit was performed by three subjects in three conditions: wearing the exosuit powered up, wearing the exosuit unpowered, and not wearing the exosuit. The test results showed that JHT-EXO could effectively reduce the ankle inversion angle by 22.11° compared to not wearing the exosuit. JHT-EXO is feasible in preventing foot drop and stabilizing flip, and its high mobility and portability show potential for gait rehabilitation of foot inversion patients. © 2024 IEEE.

关键词： Patient rehabilitation

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Characterizing permeability-porosity relationships of porous rocks using a stress sensitivity model in consideration of elastic-structural deformation and tortuosity sensitivity

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3437-3451页

作者： Ronghe Xu Liqin Wang Xiaoli Zhao Yuze Mao MIIT Key Laboratory of Aerospace Bearing Technology and Equipment Harbin Institute of TechnologyHarbin150001China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin150001China Shanghai Aerospace Control Technology Institute Shanghai201100China

Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource *** and more studies focus on how to construct stress sensitivity models to describe the relationship and obtain a comprehensive stress sensitivity of porous ***,the limitations of elastic deformation calculation and incompleteness of considered tortuosity sensitivity lead to the fact that the existing stress sensitivity models are still unsatisfactory in terms of accuracy and ***,a more accurate and generic stress sensitivity model considering elastic-structural deformation of capillary cross-section and tortuosity sensitivity is proposed in this *** elastic deformation is derived from the fractal scaling model and Hooke's *** the effects of elastic-structural deformation on tortuosity sensitivity,an empirical formula is proposed,and the conditions for its applicability are *** predictive performance of the proposed model for the permeability-porosity relationships is validated in several sets of publicly available experimental *** experimental data are from different rocks under different pressure *** mean and standard deviation of relative errors of predicted stress sensitivity with respect to experimental data are 2.63%and 1.91%.Compared with other models,the proposed model has higher accuracy and better predictive generalization *** is also found that the porosity sensitivity exponent a,which can describe permeability-porosity relationships,is 2 when only elastic deformation is considered.a decreases from 2 when structural deformation is also *** addition,a may be greater than 3 due to the increase in tortuosity sensitivity when tortuosity sensitivity is considered even if the rock is not fractured.

关键词： Stress sensitivity model Permeability-porosity relationships Elastic-structural deformation Tortuosity stress sensitivity

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Evolution and formation mechanism of rail corrugation in high-speed railways involving the longitudinal wheel-track coupling relationship

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Science china(Technological Sciences) 2024年第11期67卷 3612-3625页

作者： SHEN YiZhe ZHU ShengYang YANG JianJin ZHAI WanMing State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Rail corrugation poses a significant threat to train running safety in the field of railway ***,this study employs numerical analysis to investigate the evolution and formation mechanism of rail corrugation in high-speed railways(HSR).Firstly,a three-dimensional(3D)vehicle-track coupled dynamics(VTCD)model is established,which considers the longitudinal wheel-rail(WR)coupling relationship more ***,by integrating the USFD wear model into this 3D VTCD model,a long-term iterative wear model is developed to reproduce the corrugation evolution *** predicted corrugation exhibits two distinct wavelength components and closely matches the sample obtained from china's HSR,validating the established model in terms of ***,the formation mechanism of these two wavelength components is investigated by analyzing the harmonic behavior of vehicle-track coupled systems(VTCS)and the evolution law of rail corrugation under different calculation *** findings reveal that the 3rd-order vertical rail local bending mode(RLBM)between two wheelsets of a bogie(TW-B)is the primary factor contributing to the formation of the long-wavelength component of rail *** discrete supports of the fasteners do not affect the 3rd-order vertical RLBM,which can be stably ***,the vertical rail vibration has a substantial coupled effect on the longitudinal WR *** the 3rd-order vertical RLBM is excited,the coupled effect and the negative longitudinal WR creepage together evidently promote the formation of the short-wavelength component of rail corrugation.

关键词： vehicle-track coupled dynamics high-speed railways rail corrugation wear prediction formation mechanism

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Effect of streamlined nose length on aerodynamic performance of high-speed train with a speed of 400 km/h

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 525-540页

作者： Nianxun LI Tian LI Zhiyuan DAI Deng QIN Jiye ZHANG State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed *** appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind *** this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SNLs,is conducted using the k-ωshear stress transport(SST)turbulence *** different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 *** order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the *** simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on *** impact of SNL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure *** comparison to the original train,the train with a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic ***,the lift forces on the head and tail cars increased by 35.7%and 75.5%,*** the other hand,the train with an 18.0 m SNL exhibited a 16.5%decrease in aerodynamic ***,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,*** aerodynamic drag force of the entire train varies linearly with the SNL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SNL.

关键词： Streamlined nose length(SNL) High-speed train Aerodynamic performance Numerical simulation Flow structures

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Dynamics modeling and electromechanical coupling characteristics analysis of cage induction motors

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Science china(Technological Sciences) 2024年第3期67卷 709-724页

作者： ZHOU ZiWei CHEN ZaiGang ZHAI WanMing State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Induction motors, as typical electromechanical energy conversion devices, have received limited attention in previous studies on electromechanical coupling vibrations, precise modeling, and the use of electromechanical coupling effects for fault diagnosis and condition assessment in motor drive systems. This study proposes a comprehensive model of cage induction motors that integrates the multiple coupled circuit model with a rotor-bearing dynamics model. The model accounts for the linear increase in the magnetomotive force across the slot and incorporates the skidding characteristics of bearings in the rotor-bearing system. By calculating the time-varying mutual inductance parameters based on the air-gap distribution in the vibration environment, the electromechanical coupling vibration of the cage motor is investigated. Furthermore, this study examines the electromechanical coupling vibration characteristics influenced by various factors, including bearing clearances, radial loads, and the vertical excitation frequencies of the stators. The results show that the proposed model improves the excitation inputs for the electrical and mechanical systems of the motor compared with conventional models. Increased bearing clearance and radial load affect the current and torque similarly but have opposite effects on the slip ratio. This study provides a deeper understanding of electromechanical coupling mechanisms and facilitates the use of such phenomena for fault diagnosis and condition assessment in motor-driven systems.

关键词： cage induction motors rotor-bearing dynamics mutual inductance electromechanical testing current signal analysis

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Quasi-Static and Dynamic Collapse Behavior of Circular Foam-Filled Tubes Inspired by Bamboos

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Chinese Journal of Mechanical Engineering 2024年第6期37卷 235-257页

作者： Kai Liu Zhenhao Yu Kaiyun Wang Lin Jing State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

The axial collapse mechanical behavior and energy absorption characteristics of circular foam-filled tubes mimicking the bamboo characteristics under quasi-static and low-velocity impact loads were investigated via experiments and numerical simulations in this *** crushing deformation process,load-displacement responses,the strain field and temperature field distribution characteristics of foam-filled tubes were *** energy absorption mechanism and crashworthiness performance of specimens were evaluated and compared with conventional empty tubes.E ects of ambient temperature on axial collapse behavior and crashworthiness indices were also *** results revealed that the superior energy absorption capacity of foam-filled tubes was attributed to the strengthening e ect of bionic joints and the filling e ect of aluminium *** energy absorption(EA),specific energy absorption(SEA),and other crashworthiness indices of foam-filled tubes under axial impact load were greatly improved than that of quasi-static *** to conventional empty tubes,the foam-filled tube had a larger energyabsorbing e ectiveness factor under both quasi-static and dynamic *** increased temperature weakens the crashworthiness performance and energy absorption ability of the foam-filled *** SEA values ranged from 28.2 J/g to 22.1 J/g for the quasi-static load and 31.9 J/g to 26.3 J/g for the dynamic load when the temperature elevated from-50℃to 100℃.

关键词： Foam-filled bionic tube Collapse behaviour Crashworthiness Energy absorption Dynamic load

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Dual Transducers Co-Focusing Method for Ultrasound Stimulation in Calf Peripheral Nervous system: A Feasibility Study

Dual Transducers Co-Focusing Method for Ultrasound Stimulati...

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

作者： Zheng, Haoran Wang, Xiaoxin Zhang, Hongwei Liu, Honghai Harbin Institute of Technology Shenzhen State Key Laboratory of Robotics and System Shenzhen China

ISBN: (纸本)9781665410205

As a neuromodulation technology, ultrasound stimulation exhibits great potential due to its non-invasive and targeted nature. Low-Intensity Focused Ultrasound (LIFU) allows for precise targeting of the peripheral nervous system, enabling the elicitation of diverse sensations in the human body, including tactile, cold, heat, and pain. Current research efforts predominantly focus on ultrasound stimulation of the upper limbs, specifically the fingers. However, there is a paucity of investigation pertaining to the stimulation of the peripheral nervous system in the lower limb of the human body. Furthermore, the utilization of a singularly focused transducer for stimulation introduces anisotropy, thereby rendering it challenging to enhance the axial resolution. This study aims to explore an innovative approach using dual transducers that synergistically focus ultrasound to achieve highly precise stimulation and reduce the disparity between axial and lateral resolution. The primary objective is to investigate the feasibility of utilizing this approach for deep muscle stimulation in the human calf muscles, thus delving into the realm of lower limb neuromodulation. © 2024 IEEE.

关键词： Ultrasonics

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