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
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
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
Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive ...Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate response.However,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of time.Herein we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor application.We systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 nW.The sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on it.Moreover,there was almost no performance loss for the device as left in the air for two months.展开更多
This study presents a closed-form solution for central stress,a semi-analytical model,and a modified anisotropic semi-analytical model to efficiently calculate the forcefrequency coefficients(FFCs)of square quartz cry...This study presents a closed-form solution for central stress,a semi-analytical model,and a modified anisotropic semi-analytical model to efficiently calculate the forcefrequency coefficients(FFCs)of square quartz crystal resonators(QCRs)with different side lengths and azimuth angles under eccentrically concentrated and distributed loads.The semi-analytical model is validated by comparisons between the experimental results and the nonlinear finite element method(FEM)simulation results.Based on the semi-analytical model for the FFC and nonlinear FEM simulations,the FFC variations of square QCRs under external loads and the related mechanisms are investigated.Among the initial stresses caused by external loads,the central stress parallel to the xcrystallographic axis is the primary factor influencing the FFC of quartz.Our findings can provide practical tools for calculating the FFC,and help the design and development of square quartz force sensors.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
Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,...Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,environmental explo-ration,and tactile perception.Tactile sensors that emulate this sensory capability,particularly in the detection,decoupling,and application of normal and shear forces,have made significant strides in recent years.This review comprehensively examines the latest research advancements in tactile sensors for normal and shear force sensing,delving into the design and decoupling methods of multi-unit structures,multilayer encapsulation structures,and bionic structures.It analyzes the advantages and disadvantages of various sensing principles,including piezoresistive,capacitive,and self-powered mechanisms,and evalu-ates their application potential in health monitoring,robotics,wearable devices,smart prosthetics,and human-machine interaction.By systematically summarizing current research progress and technical challenges,this review aims to provide forward-looking insights into future research directions,driving the development of electronic skin technology to ultimately achieve tactile perception capabilities comparable to human skin.展开更多
The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field,as well as the synchronous parasitic torques,radial magnetic forc...The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field,as well as the synchronous parasitic torques,radial magnetic forces have been discussed in great detail in the literature,but always separately,for a long time.However,systematization of the phenomenon still awaits.Therefore,it is worth summarizing the completeness of the phenomena in a single study–with a new approach at the same time-in order to reveal the relationships between them.The role of rotor slot number is emphasized much more than before.New formulas derived for both synchronous torques and radial magnetic forces are used for further investigation.It will be shown that both phenomena in subject must be treated together.Formulas will be provided to take into account attenuation.Design guide will be provided to avoid dangerous rotor slot numbers.It will be shown that the generation of synchronous torques and radial magnetic forces do not depend–in this new approach-on the slot combination,but on the rotor slot number itself.展开更多
The purpose of this study is to measure the forces and torques produced in the drilling process of a non-homogenous material （bone）. An automated 5 DoF CataLyst-5 robot is used during the drilling process and it is ...The purpose of this study is to measure the forces and torques produced in the drilling process of a non-homogenous material （bone）. An automated 5 DoF CataLyst-5 robot is used during the drilling process and it is integrated to a 6 DoF force-torque sensor. A force-torque controller which is built in the Matlab Simulink environment is employed to control the drilling process of the bone. Different feed rate is used during the experimental process of the bone drilling operation. The sensor is calibrated to measure the tri-axial direction of the resultant forces and torques. The profiles of the forces and torques obtained are non-linear due to the diversity of the bone density. The profiles generated also indicated fluctuation in the interface layers of the bone.展开更多
The design of notch and barrier was optimized in order to improve the characteristics of constant torque while minimizing the cogging torque that occurs as a result of teeth and slot structure. The barrier was install...The design of notch and barrier was optimized in order to improve the characteristics of constant torque while minimizing the cogging torque that occurs as a result of teeth and slot structure. The barrier was installed in order to minimize the cogging torque and torque ripple by finite element method (FEM) with a reduced barrier width toward the center of magnetic pole. The position and width of notch, which can offset cogging torque, can be calculated with energy distribution of air-gap using Fourier series. The optimized model demonstrates a 60% decrease in the cogging torque, a 75.3% decrease in the torque ripple and a 3% increase in the operating torque when compared with the basic model.展开更多
Drilling is indispensable process and it cannot be avoided for joining composite structures used in various engineering applications. In this research article, the influence of drilling parameters on thrust force and ...Drilling is indispensable process and it cannot be avoided for joining composite structures used in various engineering applications. In this research article, the influence of drilling parameters on thrust force and torque of silica (SiO2) and alumina (Al2O3) filled into glass fabric reinforced epoxy (G-E) composites are analyzed. Drilling experiments are conducted on these composite materials using BATLIBOI make radial drilling machine. Two different drill bits (HSS and cemented carbide) are used for the experimentation. The influence of drilling parameters like cutting speed and feed on thrust force and torque on drilling of particulate filled G-E composites has been carried out. The experimental results indicated that the thrust force and torque were increased with increasing feed and cutting speed for all the composites tested. Further, it is observed that the carbide drill performed better than HSS drill during drilling of particulate filled G-E composites. The drilled surfaces are examined using scanning electron microscopy (SEM) and damage mechanisms are discussed.展开更多
The present research introduces a unique concept of scarf joint technique in friction stir welding(FSW) of aluminum alloy AA 6061-T6 plates and an investigation on weld quality.A new joint configuration with two disti...The present research introduces a unique concept of scarf joint technique in friction stir welding(FSW) of aluminum alloy AA 6061-T6 plates and an investigation on weld quality.A new joint configuration with two distinct scarf angles(75°and 60°) was considered in this study.The various aspects of welding were compared with contemporary simple square butt(SSB) joint configuration.Welding was carried out at a constant tool rotation speed(TRS),tool traverse speed(TTS) and tool tilt angle of 1100 rpm,2 mm/s and2°,respectively.The results are analyzed in terms of force and torque distribution,microstructure,macrostructure,and mechanical property perspective for different joint configurations.The study reveals the minimum amount of force and torque at 60°scarf angle joint configuration compared to that of square butt joint configuration.Macro study shows that all the joints were defect-free,and a prominent onion ring was present in the lower portion of the weld nugget(WN).Fine equiaxed grains with a minimum average grain size diameter of 6.82 μm were obtained in the WN of scarf joint configuration(SJC).The maximum ultimate tensile strength(UTS) and maximum average NZ hardness of 267 MPa and83.82 HV0.1were obtained in SJC3 at a scarf angle of 60°.It has been observed from the investigation that the joint efficiency increases from 72.5%(SSB) to 86%(SJC3) at a 60° scarf angle.This unique characteristic may lay an impetus on probable joint strength enhancement technique without increasing the production cost.展开更多
The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic...The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic standing waves having an arbitrary angle of incidence in the polar(transverse)plane.The host medium of wave propagation and the eccentric liquid-like cylinder are non-viscous.Numerical computations illustrate the theoretical analysis with particular emphases on the eccentricity of the cylinder,the angle of incidence and the dimensionless size parameters of the inner and coating cylindrical fluid materials.The method to derive the acoustical scattering,and radiation force and torque components conjointly uses modal matching with the addition theorem,which adequately account for the multiple wave interaction effects between the layer and core fluid materials.The results demonstrate that longitudinal and lateral radiation force components arise.Moreover,an axial radiation torque component is quantified and computed for the non-absorptive compound cylinder,arising from geometrical asymmetry considerations as the eccentricity increases.The computational results reveal the emergence of neutral,positive,and negative radiation force and torque depending on the size parameter of the cylinder,the eccentricity,and the angle of incidence of the insonifying field.Moreover,based on the law of energy conservation applied to scattering,numerical verification is accomplished by computing the extinction/scattering energy efficiency.The results may find some related applications in fluid dynamics,particle trapping,mixing and manipulation using acoustical standing waves.展开更多
Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonif...Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonified by plane waves progressive waves(of arbitrary incidence in the polar plane)are established and computed numerically.The modal matching method and the translational addition theorem in cylindrical coordinates are used to derive exact mathematical expressions applicable to any inner and outer cylinder sizes without any approximations,and taking into account the interaction effects between the waves propagating in the layer and those scattered from the cylindrical core.The results show that longitudinal and transverse radiation force components arise,in addition to the emergence of an axial radiation torque component acting on the non-absorptive compound cylinder due to geometrical asymmetry as the eccentricity increases.The computations demonstrate that the axial torque component,which arises due to a geometrical asymmetry,can be positive(causing counterclockwise rotation in the polar plane),negative(clockwise rotation)or neutral(rotation cancellation)depending on the size parameter of the cylinder and the amount of eccentricity.Furthermore,verification and validation of the results have been accomplished from the standpoint of energy conservation law applied to scattering,and based on the reciprocity theorem.展开更多
The calculation results of the rolling force and torque model based on Orowan's differential equation numerical solution method do not fit with the industrial measurements very well.In particular,a quite large dev...The calculation results of the rolling force and torque model based on Orowan's differential equation numerical solution method do not fit with the industrial measurements very well.In particular,a quite large deviation on the torque model was found.On the basis of analyzing the shortcomings of the existing method,an improved rolling force and torque model algorithm aided by the Process Integrated Data Application System platform is proposed.Accordingly,the calculation accuracy of the rolling torque model is improved.The improved models are verified by 1711136 records of a data platform.The improved models are also based on Orowan's differential equation.Two coefficients,namely,friction factor and forward slip,are recognized as the crucial factors to be determined from industrial measurements to improve the accuracy.Therefore,the proposed method is a hybrid method that can be used to deeply understand the rolling process and improve the model's accuracy by combining traditional plastic mechanics and data-driving global optimization algorithms.This paper proposes a new approach to studying theoretical rolling deformation models powered by the industrial data platform.展开更多
Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wi...Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wide sensing range and ability to detect three-dimensional(3D)force is still very challenging.Herein,a flexible tactile electronic skin sensor based on carbon nanotubes(CNTs)/polydimethylsiloxane(PDMS)nanocomposites is presented for 3D contact force detection.The 3D forces were acquired from combination of four specially designed cells in a sensing element.Contributed from the double-sided rough porous structure and specific surface morphology of nanocomposites,the piezoresistive sensor possesses high sensitivity of 12.1 kPa?1 within the range of 600 Pa and 0.68 kPa?1 in the regime exceeding 1 kPa for normal pressure,as well as 59.9 N?1 in the scope of<0.05 N and>2.3 N?1 in the region of<0.6 N for tangential force with ultra-low response time of 3.1 ms.In addition,multi-functional detection in human body monitoring was employed with single sensing cell and the sensor array was integrated into a robotic arm for objects grasping control,indicating the capacities in intelligent robot applications.展开更多
A six-axis force sensor with parallel 8/4-4 structure is introduced and its measurement principle is analyzed.Based on condition numbers of Jacobian matrix spectral norm of the sensor,the relationship between the forc...A six-axis force sensor with parallel 8/4-4 structure is introduced and its measurement principle is analyzed.Based on condition numbers of Jacobian matrix spectral norm of the sensor,the relationship between the force and moment isotropy and some structural parameters is deduced.Orthogonal test methods are used to determine the degree of primary and secondary factors that have significant effect on sensor characteristics.Furthermore,the relationship between each performance index and the structural parameters of the sensor is analyzed by the method of the atlas,which lays a foundation for structural optimization design of the force sensor.展开更多
Robot＇s dynamic motion error and on-line compensation based on multi-axis force sensor are dealt with.It is revealed that the reasons of the error are formed and the relations of the error are delivered.A motion equa...Robot＇s dynamic motion error and on-line compensation based on multi-axis force sensor are dealt with.It is revealed that the reasons of the error are formed and the relations of the error are delivered.A motion equation of robot＇s termination with the error is established,and then,an error matrix and an error compensation matrix of the motion equation are also defined.An on-line error＇s compensation method is put forward to decrease the displacement error,which is a degree of millimeter,shown by the result of simulation of PUMA562 robot.展开更多
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financially supported by the National Natural Science Foundation of China(Nos.52272160,U2330112,and 52002254)Sichuan Science and Technology Foundation(Nos.2020YJ0262,2021YFH0127,2022YFH0083,2022YFSY0045,and 2023YFSY0002)+1 种基金the Chunhui Plan of Ministry of Education,Fundamental Research Funds for the Central Universities,China(No.YJ201893)the Foundation of Key Laboratory of Lidar and Device,Sichuan Province,China(No.LLD2023-006)。
文摘Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate response.However,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of time.Herein we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor application.We systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 nW.The sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on it.Moreover,there was almost no performance loss for the device as left in the air for two months.
基金supported by the Ningbo Youth Science and Technology Innovation Leading Talents of China(No.2023QL020)the Ningbo Science and Technology Major of China(No.2022Z015)the K.C.Wong Magana Fund through Ningbo University。
文摘This study presents a closed-form solution for central stress,a semi-analytical model,and a modified anisotropic semi-analytical model to efficiently calculate the forcefrequency coefficients(FFCs)of square quartz crystal resonators(QCRs)with different side lengths and azimuth angles under eccentrically concentrated and distributed loads.The semi-analytical model is validated by comparisons between the experimental results and the nonlinear finite element method(FEM)simulation results.Based on the semi-analytical model for the FFC and nonlinear FEM simulations,the FFC variations of square QCRs under external loads and the related mechanisms are investigated.Among the initial stresses caused by external loads,the central stress parallel to the xcrystallographic axis is the primary factor influencing the FFC of quartz.Our findings can provide practical tools for calculating the FFC,and help the design and development of square quartz force sensors.
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 the National Key Research and Development Program of China (No.2021YFA1401103)the National Natural Science Foundation of China (Nos.61825403,61921005).
文摘Human skin,through its complex mechanoreceptor system,possesses the exceptional ability to finely perceive and dif-ferentiate multimodal mechanical stimuli,forming the biological foundation for dexterous manipulation,environmental explo-ration,and tactile perception.Tactile sensors that emulate this sensory capability,particularly in the detection,decoupling,and application of normal and shear forces,have made significant strides in recent years.This review comprehensively examines the latest research advancements in tactile sensors for normal and shear force sensing,delving into the design and decoupling methods of multi-unit structures,multilayer encapsulation structures,and bionic structures.It analyzes the advantages and disadvantages of various sensing principles,including piezoresistive,capacitive,and self-powered mechanisms,and evalu-ates their application potential in health monitoring,robotics,wearable devices,smart prosthetics,and human-machine interaction.By systematically summarizing current research progress and technical challenges,this review aims to provide forward-looking insights into future research directions,driving the development of electronic skin technology to ultimately achieve tactile perception capabilities comparable to human skin.
文摘The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field,as well as the synchronous parasitic torques,radial magnetic forces have been discussed in great detail in the literature,but always separately,for a long time.However,systematization of the phenomenon still awaits.Therefore,it is worth summarizing the completeness of the phenomena in a single study–with a new approach at the same time-in order to reveal the relationships between them.The role of rotor slot number is emphasized much more than before.New formulas derived for both synchronous torques and radial magnetic forces are used for further investigation.It will be shown that both phenomena in subject must be treated together.Formulas will be provided to take into account attenuation.Design guide will be provided to avoid dangerous rotor slot numbers.It will be shown that the generation of synchronous torques and radial magnetic forces do not depend–in this new approach-on the slot combination,but on the rotor slot number itself.
文摘The purpose of this study is to measure the forces and torques produced in the drilling process of a non-homogenous material （bone）. An automated 5 DoF CataLyst-5 robot is used during the drilling process and it is integrated to a 6 DoF force-torque sensor. A force-torque controller which is built in the Matlab Simulink environment is employed to control the drilling process of the bone. Different feed rate is used during the experimental process of the bone drilling operation. The sensor is calibrated to measure the tri-axial direction of the resultant forces and torques. The profiles of the forces and torques obtained are non-linear due to the diversity of the bone density. The profiles generated also indicated fluctuation in the interface layers of the bone.
基金Research financially supported by Human Resource Training Project for Regional Innovation of Ministry of Education,Science and Technology(MEST)National Research Foundation(NRF)the Second Stage of Brain Korea 21 Projects,Korea
文摘The design of notch and barrier was optimized in order to improve the characteristics of constant torque while minimizing the cogging torque that occurs as a result of teeth and slot structure. The barrier was installed in order to minimize the cogging torque and torque ripple by finite element method (FEM) with a reduced barrier width toward the center of magnetic pole. The position and width of notch, which can offset cogging torque, can be calculated with energy distribution of air-gap using Fourier series. The optimized model demonstrates a 60% decrease in the cogging torque, a 75.3% decrease in the torque ripple and a 3% increase in the operating torque when compared with the basic model.
文摘Drilling is indispensable process and it cannot be avoided for joining composite structures used in various engineering applications. In this research article, the influence of drilling parameters on thrust force and torque of silica (SiO2) and alumina (Al2O3) filled into glass fabric reinforced epoxy (G-E) composites are analyzed. Drilling experiments are conducted on these composite materials using BATLIBOI make radial drilling machine. Two different drill bits (HSS and cemented carbide) are used for the experimentation. The influence of drilling parameters like cutting speed and feed on thrust force and torque on drilling of particulate filled G-E composites has been carried out. The experimental results indicated that the thrust force and torque were increased with increasing feed and cutting speed for all the composites tested. Further, it is observed that the carbide drill performed better than HSS drill during drilling of particulate filled G-E composites. The drilled surfaces are examined using scanning electron microscopy (SEM) and damage mechanisms are discussed.
基金the Ministry of Human Resource and Development,Government of India for providing the financial assistantship in the form of fellowship。
文摘The present research introduces a unique concept of scarf joint technique in friction stir welding(FSW) of aluminum alloy AA 6061-T6 plates and an investigation on weld quality.A new joint configuration with two distinct scarf angles(75°and 60°) was considered in this study.The various aspects of welding were compared with contemporary simple square butt(SSB) joint configuration.Welding was carried out at a constant tool rotation speed(TRS),tool traverse speed(TTS) and tool tilt angle of 1100 rpm,2 mm/s and2°,respectively.The results are analyzed in terms of force and torque distribution,microstructure,macrostructure,and mechanical property perspective for different joint configurations.The study reveals the minimum amount of force and torque at 60°scarf angle joint configuration compared to that of square butt joint configuration.Macro study shows that all the joints were defect-free,and a prominent onion ring was present in the lower portion of the weld nugget(WN).Fine equiaxed grains with a minimum average grain size diameter of 6.82 μm were obtained in the WN of scarf joint configuration(SJC).The maximum ultimate tensile strength(UTS) and maximum average NZ hardness of 267 MPa and83.82 HV0.1were obtained in SJC3 at a scarf angle of 60°.It has been observed from the investigation that the joint efficiency increases from 72.5%(SSB) to 86%(SJC3) at a 60° scarf angle.This unique characteristic may lay an impetus on probable joint strength enhancement technique without increasing the production cost.
文摘The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic standing waves having an arbitrary angle of incidence in the polar(transverse)plane.The host medium of wave propagation and the eccentric liquid-like cylinder are non-viscous.Numerical computations illustrate the theoretical analysis with particular emphases on the eccentricity of the cylinder,the angle of incidence and the dimensionless size parameters of the inner and coating cylindrical fluid materials.The method to derive the acoustical scattering,and radiation force and torque components conjointly uses modal matching with the addition theorem,which adequately account for the multiple wave interaction effects between the layer and core fluid materials.The results demonstrate that longitudinal and lateral radiation force components arise.Moreover,an axial radiation torque component is quantified and computed for the non-absorptive compound cylinder,arising from geometrical asymmetry considerations as the eccentricity increases.The computational results reveal the emergence of neutral,positive,and negative radiation force and torque depending on the size parameter of the cylinder,the eccentricity,and the angle of incidence of the insonifying field.Moreover,based on the law of energy conservation applied to scattering,numerical verification is accomplished by computing the extinction/scattering energy efficiency.The results may find some related applications in fluid dynamics,particle trapping,mixing and manipulation using acoustical standing waves.
文摘Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonified by plane waves progressive waves(of arbitrary incidence in the polar plane)are established and computed numerically.The modal matching method and the translational addition theorem in cylindrical coordinates are used to derive exact mathematical expressions applicable to any inner and outer cylinder sizes without any approximations,and taking into account the interaction effects between the waves propagating in the layer and those scattered from the cylindrical core.The results show that longitudinal and transverse radiation force components arise,in addition to the emergence of an axial radiation torque component acting on the non-absorptive compound cylinder due to geometrical asymmetry as the eccentricity increases.The computations demonstrate that the axial torque component,which arises due to a geometrical asymmetry,can be positive(causing counterclockwise rotation in the polar plane),negative(clockwise rotation)or neutral(rotation cancellation)depending on the size parameter of the cylinder and the amount of eccentricity.Furthermore,verification and validation of the results have been accomplished from the standpoint of energy conservation law applied to scattering,and based on the reciprocity theorem.
文摘The calculation results of the rolling force and torque model based on Orowan's differential equation numerical solution method do not fit with the industrial measurements very well.In particular,a quite large deviation on the torque model was found.On the basis of analyzing the shortcomings of the existing method,an improved rolling force and torque model algorithm aided by the Process Integrated Data Application System platform is proposed.Accordingly,the calculation accuracy of the rolling torque model is improved.The improved models are verified by 1711136 records of a data platform.The improved models are also based on Orowan's differential equation.Two coefficients,namely,friction factor and forward slip,are recognized as the crucial factors to be determined from industrial measurements to improve the accuracy.Therefore,the proposed method is a hybrid method that can be used to deeply understand the rolling process and improve the model's accuracy by combining traditional plastic mechanics and data-driving global optimization algorithms.This paper proposes a new approach to studying theoretical rolling deformation models powered by the industrial data platform.
基金funding from National Natural Science Foundation of China(NSFC Nos.61774157,81771388,61874121,and 61874012)Beijing Natural Science Foundation(No.4182075)the Capital Science and Technology Conditions Platform Project(Project ID:Z181100009518014).
文摘Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wide sensing range and ability to detect three-dimensional(3D)force is still very challenging.Herein,a flexible tactile electronic skin sensor based on carbon nanotubes(CNTs)/polydimethylsiloxane(PDMS)nanocomposites is presented for 3D contact force detection.The 3D forces were acquired from combination of four specially designed cells in a sensing element.Contributed from the double-sided rough porous structure and specific surface morphology of nanocomposites,the piezoresistive sensor possesses high sensitivity of 12.1 kPa?1 within the range of 600 Pa and 0.68 kPa?1 in the regime exceeding 1 kPa for normal pressure,as well as 59.9 N?1 in the scope of<0.05 N and>2.3 N?1 in the region of<0.6 N for tangential force with ultra-low response time of 3.1 ms.In addition,multi-functional detection in human body monitoring was employed with single sensing cell and the sensor array was integrated into a robotic arm for objects grasping control,indicating the capacities in intelligent robot applications.
基金supported by the Open Foundation of Graduate Innovation Base(Laboratory)of Nanjing University of Aeronautics and Astronautics (No.kfjj20170512)the National Natural Science Foundation of China(No. 51175263)
文摘A six-axis force sensor with parallel 8/4-4 structure is introduced and its measurement principle is analyzed.Based on condition numbers of Jacobian matrix spectral norm of the sensor,the relationship between the force and moment isotropy and some structural parameters is deduced.Orthogonal test methods are used to determine the degree of primary and secondary factors that have significant effect on sensor characteristics.Furthermore,the relationship between each performance index and the structural parameters of the sensor is analyzed by the method of the atlas,which lays a foundation for structural optimization design of the force sensor.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program,No.2001AAA423300)Provincial Natural Science Foundation of Anhui,China(No.00043310)
文摘Robot＇s dynamic motion error and on-line compensation based on multi-axis force sensor are dealt with.It is revealed that the reasons of the error are formed and the relations of the error are delivered.A motion equation of robot＇s termination with the error is established,and then,an error matrix and an error compensation matrix of the motion equation are also defined.An on-line error＇s compensation method is put forward to decrease the displacement error,which is a degree of millimeter,shown by the result of simulation of PUMA562 robot.
