Understanding the complex interplay between structured light and particles is crucial for unlocking advanced optical manipulation techniques.However,existing theories for optical force/torque are often limited to smal...Understanding the complex interplay between structured light and particles is crucial for unlocking advanced optical manipulation techniques.However,existing theories for optical force/torque are often limited to small particles within the dipole regime or specific light fields,thereby lacking universality and sometimes leading to ambiguity.To overcome these limitations,we establish a fully analytical and comprehensive framework for optical force/torque based on the Cartesian multipole expansion theory,which is applicable to arbitrary-sized bi-isotropic(chiral)spherical particles immersed in arbitrary monochromatic optical fields.Rigorous expressions are thus derived,which explicitly bridge the optical force/torque with particle-propertydependent coefficients and“force/torque source”quantities characterizing the incident light structures.Such quantities identify the ultimate physical origins of optical force/torque and are systematically classified into four categories based on their parity(P)and duality(D)symmetries.Each category interacts selectively with particles exhibiting specific P and D(a)symmetries,thus inducing distinct optical forces or torques with characteristic physical behaviors.This classification establishes the mutual symmetry-breaking criteria necessary for both particles and light beams to generate optical force/torque,offering a physics-based roadmap for engineering optical manipulations such as chirality sorting,light-driven micromotors,and beyond.展开更多
The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheol...The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheological （MR） fluid is filled into the gaps between the rotor and the caps. When the viscosity of the MR fluid increases under the influence of the magnetic field, the movement of the rotor will be resisted. The output torque is made up of the torque caused by the magnetic field, the torque caused by the plastic viscosity of the MR fluid, and the torque caused by the coulomb friction. The viscous torque can be calculated by a simple method and the frictional torque can be obtained by experiments. The torque dependent on the magnetic field is obtained by electromagnetic finite dement analysis. Experiments are done on the damper prototype and the validity of the design is verified.展开更多
The six-component force/torque sensor has become one kind of the most important sensors with the ability of measuring all the external forces and torques.A novel hyperstatic six-component force/torque sensor based on ...The six-component force/torque sensor has become one kind of the most important sensors with the ability of measuring all the external forces and torques.A novel hyperstatic six-component force/torque sensor based on the Stewart platform structure,which can be used for the force measurement of the robot wrist,is proposed,and its structural optimal design,finite element analysis and calibration experimentation is presented.The characteristic of the sensor structure is analyzed in comparison with the traditional Stewart platform-based sensor.The mathematical expression of the sensor's force mapping matrix is introduced.The condition number and generalized amplifying coefficient defined by singular values of force Jacobian matrix are used to evaluate the performances of isotropy and sensitivity of the sensor respectively.The optimal design of the sensor structure is performed with the objective of achieving high measurement sensitivity and good isotropy.The sensor prototype is fabricated,and the static and dynamic characteristics of the sensor are analyzed with finite element analysis software package ANSYS.The calibration device is manufactured,and the data acquisition and processing system is developed.The theoretical and experimental study of the static calibration of the sensor prototype is carried out.The results of simulation analysis and calibration experimentation prove the feasibility of the hyperstatic sensor structure,and the contents of this paper possess theoretical significance and engineering value for the further research and practical application of the six-component force sensor.展开更多
The large manipulator outside the space cabin is a multi-degree of freedom actuator for space operations.In order to realize the automatic control and flexible operation of the space manipulator,a novel spoke structur...The large manipulator outside the space cabin is a multi-degree of freedom actuator for space operations.In order to realize the automatic control and flexible operation of the space manipulator,a novel spoke structure piezoelectric six-dimensional force/torque sensor with redundancy ability,high stiffness and good decoupling performance is innovatively proposed.Based on the deformation coordination relationship,the redundancy measurement mechanism is revealed.The mathematical models of the sensor with and without branch fault are established respectively.The finite element model is established to verify the feasibility of structure and redundancy measuring principle of the sensor.Depending on the theoretical analysis and simulation analysis,the prototype of the sensor is developed.Static and dynamic calibration experiments are carried out.The actual output voltage signal of the six-dimensional force/torque sensor is collected to establish the equation between the standard input applied load and the actual output voltage signal.Based on ant colony optimized BP algorithm,performance indexes of the sensor with and without branch fault are analyzed respectively.The experimental results show that the spoke piezoelectric sixdimensional force/torque sensor with the eight-point support structure has good accuracy and reliability.Meanwhile,it has strong decoupling characteristic that can effectively shield the coupling between dimensions.The nonlinear errors and maximum interference errors of decoupled data with and without branch faults are less than 1% and 2%,respectively.The natural frequency of the sixdimensional force sensor can reach 2856.45 Hz and has good dynamic characteristics.The research content lays a theoretical and experimental foundation for the design,development and application of the new six-dimensional force/torque sensors with redundancy.Meanwhile,it will significantly improve the research level in this field,and provide a strong guarantee for the smooth implementation of force feedback control of the space station manipulator project.展开更多
In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive...In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive sensing method,a flexural-hinged Stewart platform is designed as the flexible structure,and a straightforward optimization method considering the force and sensitivity isotropy of the sensor is proposed to determine geometric parameters which are best suited for the given external loads.The accuracy of this method is preliminarily discussed by finite element methods(FEMs).The sensor prototype is fabricated with the development of the electronic system.Calibration and dynamic loading tests for this sensor prototype are carried out.The working ranges of this sensor prototype are 30 N and 300 N·mm,and resolutions are 0.08 N in radial directions,0.25 N in axial direction,and 2.4 N·mm in rotational directions.It also exhibits a good capability for a typical dynamic force sensing at a frequency close to the normal heart rate of an adult.The sensor is compatible with surgical instruments for force feedback in RMIS.展开更多
This paper presents a new designed miniature six DOF （degree of freedom） force/torque sensor. This sensor is fully integrated with a micro DSP （digital signal processor）, so all the signal conditioning, A/D, decou...This paper presents a new designed miniature six DOF （degree of freedom） force/torque sensor. This sensor is fully integrated with a micro DSP （digital signal processor）, so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate.展开更多
A novel orthogonal-parallel six-axis force/torque sensor is studied based on a modified Stewart platform architecture,and the optimal design and experiment research of the sensor are discussed.Firstly,the model of ort...A novel orthogonal-parallel six-axis force/torque sensor is studied based on a modified Stewart platform architecture,and the optimal design and experiment research of the sensor are discussed.Firstly,the model of orthogonal parallel six-axis force/torque sensor based on improved Stewart platform architecture and its static mathematical model are proposed.Secondly,according to the actual working condition of the sensor,the sensor is optimized and the optimal solution is obtained.Then,the experimental prototype and calibration system is developed.Finally,the superiority of the sensor structure and the effectiveness of the optimization method are verified by calibration experiments.The results of the proposed method are useful for the further research and application of the orthogonal-parallel six-axis force/torque sensor.展开更多
This article investigates the radial electromagnetic force,vibration,and noise phenomenon in a low-speed,hightorque density spoke-type permanent magnet synchronous machine(ST-PMSM)designed with assisted poles having s...This article investigates the radial electromagnetic force,vibration,and noise phenomenon in a low-speed,hightorque density spoke-type permanent magnet synchronous machine(ST-PMSM)designed with assisted poles having symmetric and asymmetric topologies.Firstly,an analytical expression for the machine radial electromagnetic force(REMF)is derived to quickly estimate the REMF characteristics for the ST-PMSM with assisted poles having symmetric and asymmetric topologies.The 2D-Fourier decomposition method is applied to investigate the radial electromagnetic force harmonics(REMFHs).Secondly,Finite element(FE)models are designed for the machine structural analysis.Subsequently,the FE models and modal analysis are explored for different design cases of the analyzed machine.Lastly,vibration and noise behavior are investigated using an FE approach for the machine designs under symmetric and asymmetric assisted poles topologies.The findings indicate an increase in the richness of REMFHs,alongside a decrease in both the fundamental frequency and the lowest non-zero order of REMF,attributed to the presence of asymmetric assisted poles.Consequently,it is investigated that while considering the vibration and noise response in STPMSMs designed with asymmetric assisted poles topologies,it is essential to thoroughly account for induced non-zero low-order harmonics and their optimization for better vibration and noise performance.展开更多
The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input mult...The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.展开更多
A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stre...A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stress−strain hysteresis curves of soil profiles on the pile side with and without cement-soil reinforced piles indicates that cement-soil reinforced piles not only bear more tremendous shear stress but also have smaller strains under the action of cyclic shear stress.Furthermore,the cement-soil on the pile side not only shares part of the shear stress and modifies the bending moment distribution but also significantly enhances the resistance of the pile-side soil,reducing the lateral displacement of the superstructure.Cement-soil reinforcement reduced shear strains,inhibited sand liquefaction,and reduced superstructure displacements by 27%−47%(instantaneous)and 40%−65%(permanent).The proportion of horizontal load sharing between cement-soil reinforcement and saturated sand is considered,along with the change pattern of the subgrade reaction after sand liquefaction.An equivalent subgrade reaction calculation method is proposed,which accounts for the horizontal load-sharing ratios of soils with two different strengths.The test results indicate that the pile stress and displacement,estimated using the equivalent subgrade reaction,are in good agreement with the observed results.展开更多
Efficient torque allocation in over-actuated vehicles poses a central challenge in the domain of advanced vehicle control.These vehicles,featuring redundant actuators,provide an exceptional avenue for enhancing perfor...Efficient torque allocation in over-actuated vehicles poses a central challenge in the domain of advanced vehicle control.These vehicles,featuring redundant actuators,provide an exceptional avenue for enhancing performance,stability,and efficiency.This paper presents a pioneering tendency for torque allocation in the context of over-actuated vehicles,particularly inwheel motor(IWM)driven electric vehicles.We introduce a systematic methodology grounded in analytical modeling,allowing for the efficient reconciliation of multiple,often conflicting objectives.The explicit functions are analytically modeled to enhance stability and energy economy.Additionally,a fuzzy logic-based torque allocation strategy is developed and compared,along with other literature methods,with the analytical models.Simulations are conducted in a joint simulation between Simulink/MATLAB and SCANeR Studio vehicle dynamics simulator,followed by validation on a real-world dataset.Our findings elucidate the proficiency of the analytical models on vehicle performance,stability,computational efficiency,and energy consumption.展开更多
We report the development of the[Pt_(0.75)Ti_(0.25)/Co-Ni multilayer/Ta]_n superlattice with strong spin-orbit torque,large perpendicular magnetic anisotropy,and remarkably low switching current density.We demonstrate...We report the development of the[Pt_(0.75)Ti_(0.25)/Co-Ni multilayer/Ta]_n superlattice with strong spin-orbit torque,large perpendicular magnetic anisotropy,and remarkably low switching current density.We demonstrate that the efficiency of the spin-orbit torque increases nearly linearly with the repetition number n,which is in excellent agreement with the spin Hall effect of the Pt_(0.75)Ti_(0.25)being essentially the only source of the observed spin-orbit torque.The perpendicular magnetic anisotropy field is also substantially enhanced by more than a factor of 2 as n increases from 1 to6.The[Pt_(0.75)Ti_(0.25)/Co-Ni multilayers/Ta]_n superlattice additionally exhibits deterministic,low-current-density magnetization switching despite the very large total layer thicknesses.The unique combination of strong spin-orbit torque,robust perpendicular magnetic anisotropy,low-current-density switching,and excellent high thermal stability makes the[Pt_(0.75)Ti_(0.25)/Co-Ni multilayer/Ta]_n superlattice a highly compelling material candidate for ultrafast,energy-efficient,and long-data-retention spintronic technologies.展开更多
Considering the Hamaker constant,inclusion size,and distance between inclusions on the surface of the molten steel,a new collision model of the inclusions on the surface of the molten steel was established based on in...Considering the Hamaker constant,inclusion size,and distance between inclusions on the surface of the molten steel,a new collision model of the inclusions on the surface of the molten steel was established based on in-situ observed results of the collision process of different types of inclusions on the surface of the molten steel.The developed model can be used to calculate the attraction of inclusions on the surface of the molten steel including Al_(2)O_(3)MgO,SiO_(2),etc.展开更多
Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pell...Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pellets.Addressing the gap in the application of organically-intercalated modified bentonite in the pelletizing field,this study introduces an innovative modification process for bentonite that employs the synergistic effect of mechanical force and dimethyl sulfoxide to enhance the intercalation of organic compounds within bentonite,thus significantly enhancing its binding performance.The colloid value and swell capacity of modified bentonite(98.5 m L/3g and 55.0 m L/g)were much higher than the original bentonite(90.5 m L/3g and 17.5 m L/g).With the decrease of bentonite dosage from1.5wt%to 1.0wt%,the drop number of green pellets from a height of 0.5 m and the compressive strengths of roasted pellets using the modified bentonite(6.0 times and 2916 N per pellet)were significantly higher than those of the original bentonite(4.0 times and 2739 N per pellet).This study provides a comprehensive analysis of the intercalation modification mechanism of bentonite,offering crucial technical insights for the development of high-performance modified bentonite as iron ore pellet binders.展开更多
Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior ...Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior regulation and adhesion measurement is developed.Micropillar arrays with high and low densities are designed to explore the role of substrate topography in the behavior of human bone marrow mesenchymal stem cells.In addition,a method is established for quantifying weak cell adhesion forces on the basis of micropillar deflections.The results show that cell cytoplasmic adhesion is greater on a low-density micropillar array than that on a high-density array and is localized mainly in the perinuclear region of the cytoplasm rather than in pseudopods.It is also found that the micropillar array topography facilitates the oriented spreading of cell morphology and pseudopod formation,and a reduction in focal adhesion aggregation and F-actin polarization compared with a flat substrate.Notably,cells cultured on a low-density micropillar array exhibited a higher number of pseudopods,stronger adhesion forces,and greater stiffness compared with those on a high-density array.In summary,this work employs an adhesion force sensor,immunofluorescence staining,and atomic force microscopy to investigate the mechanical properties of cells and elucidate the mechanisms by which micropillar topographical cues regulate the adhesion of mesenchymal stem cells to the substrate.The micropillar array force sensor developed in this study provides an effective tool for simultaneously modulating cell behavior and quantifying adhesion forces,offering valuable insights for biomechanical research.展开更多
The rapid development of new-quality productive forces(NQPF)has intensified the demand for high-level innovative talent.As a representative of NQPF,generative artificial intelligence(GenAI)offers powerful tools to res...The rapid development of new-quality productive forces(NQPF)has intensified the demand for high-level innovative talent.As a representative of NQPF,generative artificial intelligence(GenAI)offers powerful tools to reshape talent cultivation but also presents significant challenges,including skill hollowing,ethical risks,and a growing disconnect between education and industry needs.Currently,graduate-level software engineering education struggles with outdated curricula and insufficient alignment with practical demands.In this paper,we propose a dual-core collaborative framework driven by“GenAI technology”and“industry demand”.Under this framework,we design a four-dimensional capability development path to enhance graduate students’innovation in software engineering practice.This path focuses on①scientific research innovation,②engineering problem-solving,③cross-domain collaborative evolution,and④ethical risk governance.The proposed approach promotes a shift from traditional knowledge transfer to human-machine collaborative innovation,aligning talent cultivation with the demands of the NQPF.展开更多
Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To a...Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To address the ambiguity surrounding its micro-level empowerment mechanism,this paper empirically examines the impact of data elements on enterprises'new quality productive forces and its transmission channels using panel data of Chinese A-share listed firms from 2014 to 2023.The results show that data elements significantly improve the level of enterprises'new quality productive forces.Heterogeneity analysis indicates that this promotional effect is more pronounced in non-state-owned enterprises,large-scale enterprises,and low-leverage enterprises.Mechanism tests confirm that data elements empower new quality productive forces through three paths:enhancing enterprise innovation capability,improving internal operational efficiency,and promoting inter-firm collaboration efficiency.This study provides empirical evidence for understanding the micro-level empowerment logic of data elements and offers theoretical references and practical implications for advancing the deep integration of the digital economy and the real economy.展开更多
In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is under...In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is undergoing a profound paradigm shift.The traditional rural division of labor pattern,which depends on tangible factors such as land,labor,and capital,has increasingly encountered developmental challenges characterized by diminishing marginal returns and a detrimental cycle of internal competition.The new quality productive force,centered on data,algorithms,green technologies,bioengineering,and clean energy,offers a potential pathway for the rural division of labor system to overcome the"low-level equilibrium".This force is characterized by attributes such as non-exclusivity,replicability,network collaboration,and ecological compatibility.This paper develops a three-dimensional collaborative analytical framework encompassing"technology,institution,and culture".It systematically elucidates the internal logic by which new quality productive forces drive the transformation of the rural division of labor from"quantitative factor matching"to"qualitative structural reorganization"through three principal mechanisms:technology embedding,institutional reconstruction,and cultural coupling.Furthermore,the study proposes corresponding policy recommendations,thereby offering theoretical insights to support the modernization of China s agriculture and rural areas,as well as the development of a strong agricultural country.展开更多
Correction to:Nuclear Science and Techniques(2025)36:111 https://doi.org/10.1007/s41365-025-01681-9.In the sentence beginning‘The weights of the parameters used for the…’in this article,the text‘RCSs’should have ...Correction to:Nuclear Science and Techniques(2025)36:111 https://doi.org/10.1007/s41365-025-01681-9.In the sentence beginning‘The weights of the parameters used for the…’in this article,the text‘RCSs’should have read‘SCRs’.In Table 7 of this article,the column header ρ_fuel was incorrect and should have read CPv_fuel.For completeness and transparency,the old incorrect version and the corrected version of Table 7 are displayed below.展开更多
Nanodroplet impact on nanoscale material interfaces is widely involved in nanoscience and nanotechnology,affecting the technical reliability through complicated liquid‒solid interaction force,that is,the droplet impac...Nanodroplet impact on nanoscale material interfaces is widely involved in nanoscience and nanotechnology,affecting the technical reliability through complicated liquid‒solid interaction force,that is,the droplet impact force.However,our understanding of the nanodroplet impact force is still blank.Herein,we reveal that the nanoscale size(∼10 nm)and high impact velocity(>100 m/s)of nanodroplets lead to unique characteristics of impact force,significantly differing from those ofmacrodroplets(∼1 mm).The nanodroplet impact force profile holds a single-peak feature,which is independent of droplet parameters and material wettability.The significant water-hammer pressure induces the abnormal rising of impact force,yielding unexpectedly high peak values governed by the Mach number(more than 10 orders of magnitude higher than droplet gravity).Our findings of droplet impact force at the nanoscale reveal the potential challenge of the damage of material surfaces by nanodroplet impact,highlighting one crucial factor for advancing nanolithography and nanoprinting.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12204117,12564043,12174076,12074084,and 12074169)the Guangxi Science and Technology Project(Grant Nos.2023GXNSFFA026002,2024GXNSFBA010261,2021GXNSFDA196001,and AD23026117)+3 种基金the Open Project of State Key Laboratory of Surface Physics in Fudan University(Grant No.KF2022_15)the Guangdong Province Talent Recruitment Program(Grant No.2021QN02C103)supported by the Research Grants Council of Hong Kong(Grant Nos.16310422 and AoE/P-502/20)the Innovation Project of Guangxi Graduate Education(Grant No.11241018)。
文摘Understanding the complex interplay between structured light and particles is crucial for unlocking advanced optical manipulation techniques.However,existing theories for optical force/torque are often limited to small particles within the dipole regime or specific light fields,thereby lacking universality and sometimes leading to ambiguity.To overcome these limitations,we establish a fully analytical and comprehensive framework for optical force/torque based on the Cartesian multipole expansion theory,which is applicable to arbitrary-sized bi-isotropic(chiral)spherical particles immersed in arbitrary monochromatic optical fields.Rigorous expressions are thus derived,which explicitly bridge the optical force/torque with particle-propertydependent coefficients and“force/torque source”quantities characterizing the incident light structures.Such quantities identify the ultimate physical origins of optical force/torque and are systematically classified into four categories based on their parity(P)and duality(D)symmetries.Each category interacts selectively with particles exhibiting specific P and D(a)symmetries,thus inducing distinct optical forces or torques with characteristic physical behaviors.This classification establishes the mutual symmetry-breaking criteria necessary for both particles and light beams to generate optical force/torque,offering a physics-based roadmap for engineering optical manipulations such as chirality sorting,light-driven micromotors,and beyond.
基金The National Basic Research Program of China(973Program) (No2002CB312102)the National Natural ScienceFoundation of China (No60675047)
文摘The damper is capable of providing a continuously variable dampering force/torque in response to a magnetic field. It consists of an upside cap and an underside cap with a rotor located between them, the magneto-rheological （MR） fluid is filled into the gaps between the rotor and the caps. When the viscosity of the MR fluid increases under the influence of the magnetic field, the movement of the rotor will be resisted. The output torque is made up of the torque caused by the magnetic field, the torque caused by the plastic viscosity of the MR fluid, and the torque caused by the coulomb friction. The viscous torque can be calculated by a simple method and the frictional torque can be obtained by experiments. The torque dependent on the magnetic field is obtained by electromagnetic finite dement analysis. Experiments are done on the damper prototype and the validity of the design is verified.
基金supported by National Natural Science Foundation of China(Grant No.50575192)Hebei Provincial Natural Science Foundation of China(Grant No.E2007000349)
文摘The six-component force/torque sensor has become one kind of the most important sensors with the ability of measuring all the external forces and torques.A novel hyperstatic six-component force/torque sensor based on the Stewart platform structure,which can be used for the force measurement of the robot wrist,is proposed,and its structural optimal design,finite element analysis and calibration experimentation is presented.The characteristic of the sensor structure is analyzed in comparison with the traditional Stewart platform-based sensor.The mathematical expression of the sensor's force mapping matrix is introduced.The condition number and generalized amplifying coefficient defined by singular values of force Jacobian matrix are used to evaluate the performances of isotropy and sensitivity of the sensor respectively.The optimal design of the sensor structure is performed with the objective of achieving high measurement sensitivity and good isotropy.The sensor prototype is fabricated,and the static and dynamic characteristics of the sensor are analyzed with finite element analysis software package ANSYS.The calibration device is manufactured,and the data acquisition and processing system is developed.The theoretical and experimental study of the static calibration of the sensor prototype is carried out.The results of simulation analysis and calibration experimentation prove the feasibility of the hyperstatic sensor structure,and the contents of this paper possess theoretical significance and engineering value for the further research and practical application of the six-component force sensor.
基金supported by the National Natural Science Foundation of China(No.51875250)a Project of Shandong Province Higher Educational Youth Innovation Science and Technology Program,China(No.2019KJB018)a Project of the“20 Regulations for New Universities”Funding Program of Jinan,China(No.202228116)。
文摘The large manipulator outside the space cabin is a multi-degree of freedom actuator for space operations.In order to realize the automatic control and flexible operation of the space manipulator,a novel spoke structure piezoelectric six-dimensional force/torque sensor with redundancy ability,high stiffness and good decoupling performance is innovatively proposed.Based on the deformation coordination relationship,the redundancy measurement mechanism is revealed.The mathematical models of the sensor with and without branch fault are established respectively.The finite element model is established to verify the feasibility of structure and redundancy measuring principle of the sensor.Depending on the theoretical analysis and simulation analysis,the prototype of the sensor is developed.Static and dynamic calibration experiments are carried out.The actual output voltage signal of the six-dimensional force/torque sensor is collected to establish the equation between the standard input applied load and the actual output voltage signal.Based on ant colony optimized BP algorithm,performance indexes of the sensor with and without branch fault are analyzed respectively.The experimental results show that the spoke piezoelectric sixdimensional force/torque sensor with the eight-point support structure has good accuracy and reliability.Meanwhile,it has strong decoupling characteristic that can effectively shield the coupling between dimensions.The nonlinear errors and maximum interference errors of decoupled data with and without branch faults are less than 1% and 2%,respectively.The natural frequency of the sixdimensional force sensor can reach 2856.45 Hz and has good dynamic characteristics.The research content lays a theoretical and experimental foundation for the design,development and application of the new six-dimensional force/torque sensors with redundancy.Meanwhile,it will significantly improve the research level in this field,and provide a strong guarantee for the smooth implementation of force feedback control of the space station manipulator project.
基金Project(SS2012AA041601)supported by National High Technology Research and Development Program of ChinaProject(81201150)supported by the National Natural Science Foundation of China
文摘In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive sensing method,a flexural-hinged Stewart platform is designed as the flexible structure,and a straightforward optimization method considering the force and sensitivity isotropy of the sensor is proposed to determine geometric parameters which are best suited for the given external loads.The accuracy of this method is preliminarily discussed by finite element methods(FEMs).The sensor prototype is fabricated with the development of the electronic system.Calibration and dynamic loading tests for this sensor prototype are carried out.The working ranges of this sensor prototype are 30 N and 300 N·mm,and resolutions are 0.08 N in radial directions,0.25 N in axial direction,and 2.4 N·mm in rotational directions.It also exhibits a good capability for a typical dynamic force sensing at a frequency close to the normal heart rate of an adult.The sensor is compatible with surgical instruments for force feedback in RMIS.
基金Supported by the National Natural Science Foundation of China （ No. 60275032 ） and the Supported bv the High Technology Research and Development Programme of China （ No. 2003AA404220）.
文摘This paper presents a new designed miniature six DOF （degree of freedom） force/torque sensor. This sensor is fully integrated with a micro DSP （digital signal processor）, so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate.
基金Supported by the National Natural Science Foundation of China(No.51505124)Foster Fund Projects of North China University of Science and Technology(No.JP201505)the Science and Technology Research Project of Hebei Province(No.ZD2020151).
文摘A novel orthogonal-parallel six-axis force/torque sensor is studied based on a modified Stewart platform architecture,and the optimal design and experiment research of the sensor are discussed.Firstly,the model of orthogonal parallel six-axis force/torque sensor based on improved Stewart platform architecture and its static mathematical model are proposed.Secondly,according to the actual working condition of the sensor,the sensor is optimized and the optimal solution is obtained.Then,the experimental prototype and calibration system is developed.Finally,the superiority of the sensor structure and the effectiveness of the optimization method are verified by calibration experiments.The results of the proposed method are useful for the further research and application of the orthogonal-parallel six-axis force/torque sensor.
基金supported by the National Key Research and Developmen Program of China(2022YFB3403100)。
文摘This article investigates the radial electromagnetic force,vibration,and noise phenomenon in a low-speed,hightorque density spoke-type permanent magnet synchronous machine(ST-PMSM)designed with assisted poles having symmetric and asymmetric topologies.Firstly,an analytical expression for the machine radial electromagnetic force(REMF)is derived to quickly estimate the REMF characteristics for the ST-PMSM with assisted poles having symmetric and asymmetric topologies.The 2D-Fourier decomposition method is applied to investigate the radial electromagnetic force harmonics(REMFHs).Secondly,Finite element(FE)models are designed for the machine structural analysis.Subsequently,the FE models and modal analysis are explored for different design cases of the analyzed machine.Lastly,vibration and noise behavior are investigated using an FE approach for the machine designs under symmetric and asymmetric assisted poles topologies.The findings indicate an increase in the richness of REMFHs,alongside a decrease in both the fundamental frequency and the lowest non-zero order of REMF,attributed to the presence of asymmetric assisted poles.Consequently,it is investigated that while considering the vibration and noise response in STPMSMs designed with asymmetric assisted poles topologies,it is essential to thoroughly account for induced non-zero low-order harmonics and their optimization for better vibration and noise performance.
基金co-supported by the National Natural Science Foundation of China(No.52125504)the Liaoning Revitalization Talents Program(No.XLYC2202017)Dalian Support Policy Project for Innovation of Technological Talents(No.2023RG001)。
文摘The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.
基金Project(52078129)supported by the National Natural Science Foundation of ChinaProject(MTF2023009)supported by the Open Project of Key Laboratory of Transport Industry of Comprehensive Transportation Theory(Nanjing Modern Multimodal Transportation Laboratory),ChinaProject(2242024K40037)supported by the Fundamental Research Funds for the Central Universities,China。
文摘A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stress−strain hysteresis curves of soil profiles on the pile side with and without cement-soil reinforced piles indicates that cement-soil reinforced piles not only bear more tremendous shear stress but also have smaller strains under the action of cyclic shear stress.Furthermore,the cement-soil on the pile side not only shares part of the shear stress and modifies the bending moment distribution but also significantly enhances the resistance of the pile-side soil,reducing the lateral displacement of the superstructure.Cement-soil reinforcement reduced shear strains,inhibited sand liquefaction,and reduced superstructure displacements by 27%−47%(instantaneous)and 40%−65%(permanent).The proportion of horizontal load sharing between cement-soil reinforcement and saturated sand is considered,along with the change pattern of the subgrade reaction after sand liquefaction.An equivalent subgrade reaction calculation method is proposed,which accounts for the horizontal load-sharing ratios of soils with two different strengths.The test results indicate that the pile stress and displacement,estimated using the equivalent subgrade reaction,are in good agreement with the observed results.
基金carried out within the framework of the V3EA Project“Electric,Energy Efficient,and Autonomous Vehicle”(2021-2025)supported by the Research National Agency(ANR)of the French Government。
文摘Efficient torque allocation in over-actuated vehicles poses a central challenge in the domain of advanced vehicle control.These vehicles,featuring redundant actuators,provide an exceptional avenue for enhancing performance,stability,and efficiency.This paper presents a pioneering tendency for torque allocation in the context of over-actuated vehicles,particularly inwheel motor(IWM)driven electric vehicles.We introduce a systematic methodology grounded in analytical modeling,allowing for the efficient reconciliation of multiple,often conflicting objectives.The explicit functions are analytically modeled to enhance stability and energy economy.Additionally,a fuzzy logic-based torque allocation strategy is developed and compared,along with other literature methods,with the analytical models.Simulations are conducted in a joint simulation between Simulink/MATLAB and SCANeR Studio vehicle dynamics simulator,followed by validation on a real-world dataset.Our findings elucidate the proficiency of the analytical models on vehicle performance,stability,computational efficiency,and energy consumption.
基金supported by the Beijing Natural Science Foundation(Grant No.Z230006)the National Key Research and Development Program of China(Grant No.2022YFA1204000)the National Natural Science Foundation of China(Grant Nos.12274405 and 12393831)。
文摘We report the development of the[Pt_(0.75)Ti_(0.25)/Co-Ni multilayer/Ta]_n superlattice with strong spin-orbit torque,large perpendicular magnetic anisotropy,and remarkably low switching current density.We demonstrate that the efficiency of the spin-orbit torque increases nearly linearly with the repetition number n,which is in excellent agreement with the spin Hall effect of the Pt_(0.75)Ti_(0.25)being essentially the only source of the observed spin-orbit torque.The perpendicular magnetic anisotropy field is also substantially enhanced by more than a factor of 2 as n increases from 1 to6.The[Pt_(0.75)Ti_(0.25)/Co-Ni multilayers/Ta]_n superlattice additionally exhibits deterministic,low-current-density magnetization switching despite the very large total layer thicknesses.The unique combination of strong spin-orbit torque,robust perpendicular magnetic anisotropy,low-current-density switching,and excellent high thermal stability makes the[Pt_(0.75)Ti_(0.25)/Co-Ni multilayer/Ta]_n superlattice a highly compelling material candidate for ultrafast,energy-efficient,and long-data-retention spintronic technologies.
基金support from the National Natural Science Foundation of China(Grant No.U22A20171)the National Key Research and Development Program Project(2023YFB3709901)+3 种基金the China Baowu Low Carbon Metallurgical Innovation Fund(BWLCF202315)the Pangang-USTB Vanadium and Titanium Research Institute Research Projectthe High Steel Center(HSC)at North China University of TechnologyYanshan University and University of Science and Technology Beijing,China.
文摘Considering the Hamaker constant,inclusion size,and distance between inclusions on the surface of the molten steel,a new collision model of the inclusions on the surface of the molten steel was established based on in-situ observed results of the collision process of different types of inclusions on the surface of the molten steel.The developed model can be used to calculate the attraction of inclusions on the surface of the molten steel including Al_(2)O_(3)MgO,SiO_(2),etc.
基金financial support by the National Key Research and Development Program of China(No.2023YFC2907801)the Hunan Provincial Natural Science Foundation of China(No.2023JJ40760)the Scientific and Technological Project of Yunnan Precious Metals Laboratory,China(No.YPML-2023050276)。
文摘Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pellets.Addressing the gap in the application of organically-intercalated modified bentonite in the pelletizing field,this study introduces an innovative modification process for bentonite that employs the synergistic effect of mechanical force and dimethyl sulfoxide to enhance the intercalation of organic compounds within bentonite,thus significantly enhancing its binding performance.The colloid value and swell capacity of modified bentonite(98.5 m L/3g and 55.0 m L/g)were much higher than the original bentonite(90.5 m L/3g and 17.5 m L/g).With the decrease of bentonite dosage from1.5wt%to 1.0wt%,the drop number of green pellets from a height of 0.5 m and the compressive strengths of roasted pellets using the modified bentonite(6.0 times and 2916 N per pellet)were significantly higher than those of the original bentonite(4.0 times and 2739 N per pellet).This study provides a comprehensive analysis of the intercalation modification mechanism of bentonite,offering crucial technical insights for the development of high-performance modified bentonite as iron ore pellet binders.
基金supported by the National Natural Science Foundation of China(Grant No.32371471).
文摘Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior regulation and adhesion measurement is developed.Micropillar arrays with high and low densities are designed to explore the role of substrate topography in the behavior of human bone marrow mesenchymal stem cells.In addition,a method is established for quantifying weak cell adhesion forces on the basis of micropillar deflections.The results show that cell cytoplasmic adhesion is greater on a low-density micropillar array than that on a high-density array and is localized mainly in the perinuclear region of the cytoplasm rather than in pseudopods.It is also found that the micropillar array topography facilitates the oriented spreading of cell morphology and pseudopod formation,and a reduction in focal adhesion aggregation and F-actin polarization compared with a flat substrate.Notably,cells cultured on a low-density micropillar array exhibited a higher number of pseudopods,stronger adhesion forces,and greater stiffness compared with those on a high-density array.In summary,this work employs an adhesion force sensor,immunofluorescence staining,and atomic force microscopy to investigate the mechanical properties of cells and elucidate the mechanisms by which micropillar topographical cues regulate the adhesion of mesenchymal stem cells to the substrate.The micropillar array force sensor developed in this study provides an effective tool for simultaneously modulating cell behavior and quantifying adhesion forces,offering valuable insights for biomechanical research.
基金supported in part by the Graduate Education Reform Research Project of Hubei University of Technology under Grant 2024YB003the Hubei University of Arts and Science,Teaching Research Project,under Grant JY2025018.
文摘The rapid development of new-quality productive forces(NQPF)has intensified the demand for high-level innovative talent.As a representative of NQPF,generative artificial intelligence(GenAI)offers powerful tools to reshape talent cultivation but also presents significant challenges,including skill hollowing,ethical risks,and a growing disconnect between education and industry needs.Currently,graduate-level software engineering education struggles with outdated curricula and insufficient alignment with practical demands.In this paper,we propose a dual-core collaborative framework driven by“GenAI technology”and“industry demand”.Under this framework,we design a four-dimensional capability development path to enhance graduate students’innovation in software engineering practice.This path focuses on①scientific research innovation,②engineering problem-solving,③cross-domain collaborative evolution,and④ethical risk governance.The proposed approach promotes a shift from traditional knowledge transfer to human-machine collaborative innovation,aligning talent cultivation with the demands of the NQPF.
文摘Against the backdrop of profound restructuring in the global industrial and supply chains,data elements have emerged as a critical force driving the transformation of enterprises'new quality productive forces.To address the ambiguity surrounding its micro-level empowerment mechanism,this paper empirically examines the impact of data elements on enterprises'new quality productive forces and its transmission channels using panel data of Chinese A-share listed firms from 2014 to 2023.The results show that data elements significantly improve the level of enterprises'new quality productive forces.Heterogeneity analysis indicates that this promotional effect is more pronounced in non-state-owned enterprises,large-scale enterprises,and low-leverage enterprises.Mechanism tests confirm that data elements empower new quality productive forces through three paths:enhancing enterprise innovation capability,improving internal operational efficiency,and promoting inter-firm collaboration efficiency.This study provides empirical evidence for understanding the micro-level empowerment logic of data elements and offers theoretical references and practical implications for advancing the deep integration of the digital economy and the real economy.
基金Supported by Key Project of Jiangsu Education Science Planning"Research on the Structural Adjustment of Higher Education in Jiangsu in the Context of High-Quality Economic Development"(B/2021/01/67).
文摘In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is undergoing a profound paradigm shift.The traditional rural division of labor pattern,which depends on tangible factors such as land,labor,and capital,has increasingly encountered developmental challenges characterized by diminishing marginal returns and a detrimental cycle of internal competition.The new quality productive force,centered on data,algorithms,green technologies,bioengineering,and clean energy,offers a potential pathway for the rural division of labor system to overcome the"low-level equilibrium".This force is characterized by attributes such as non-exclusivity,replicability,network collaboration,and ecological compatibility.This paper develops a three-dimensional collaborative analytical framework encompassing"technology,institution,and culture".It systematically elucidates the internal logic by which new quality productive forces drive the transformation of the rural division of labor from"quantitative factor matching"to"qualitative structural reorganization"through three principal mechanisms:technology embedding,institutional reconstruction,and cultural coupling.Furthermore,the study proposes corresponding policy recommendations,thereby offering theoretical insights to support the modernization of China s agriculture and rural areas,as well as the development of a strong agricultural country.
文摘Correction to:Nuclear Science and Techniques(2025)36:111 https://doi.org/10.1007/s41365-025-01681-9.In the sentence beginning‘The weights of the parameters used for the…’in this article,the text‘RCSs’should have read‘SCRs’.In Table 7 of this article,the column header ρ_fuel was incorrect and should have read CPv_fuel.For completeness and transparency,the old incorrect version and the corrected version of Table 7 are displayed below.
基金the Beijing Nova Program(no.20240484595)the National Natural Science Foundation of China(no.52406104).
文摘Nanodroplet impact on nanoscale material interfaces is widely involved in nanoscience and nanotechnology,affecting the technical reliability through complicated liquid‒solid interaction force,that is,the droplet impact force.However,our understanding of the nanodroplet impact force is still blank.Herein,we reveal that the nanoscale size(∼10 nm)and high impact velocity(>100 m/s)of nanodroplets lead to unique characteristics of impact force,significantly differing from those ofmacrodroplets(∼1 mm).The nanodroplet impact force profile holds a single-peak feature,which is independent of droplet parameters and material wettability.The significant water-hammer pressure induces the abnormal rising of impact force,yielding unexpectedly high peak values governed by the Mach number(more than 10 orders of magnitude higher than droplet gravity).Our findings of droplet impact force at the nanoscale reveal the potential challenge of the damage of material surfaces by nanodroplet impact,highlighting one crucial factor for advancing nanolithography and nanoprinting.
