Force feedback bilateral teleoperation represents a pivotal advancement in control technology,finding widespread application in hazardous material transportation,perilous environments,space and deep-sea exploration,an...Force feedback bilateral teleoperation represents a pivotal advancement in control technology,finding widespread application in hazardous material transportation,perilous environments,space and deep-sea exploration,and healthcare domains.This paper traces the evolutionary trajectory of force feedback bilateral teleoperation from its conceptual inception to its current complexity.It elucidates the fundamental principles underpinning interaction forces and tactile exchanges,with a specific emphasis on the crucial role of tactile devices.In this review,a quantitative analysis of force feedback bilateral teleoperation development trends from 2011 to 2024 has been conducted,utilizing published journal article data as the primary source of information.The review accentuates classical control frameworks and algorithms,while also delving into existing research advancements and prospec-tive breakthrough directions.Moreover,it explores specific practical scenarios ranging from intricate surgeries to hazardous environment exploration,underscoring the technology’s potential to revolutionize industries by augmenting human manipulation of remote systems.This underscores the pivotal role of force feedback bilateral teleoperation as a transformative human-machine interface,capable of shaping flexible control strategies and addressing technological bottlenecks.Future research endeavors in force feedback bilateral teleoperation are expected to prioritize the creation of more immersive experiences,overcoming technical hurdles,fortifying human-machine collaboration,and broadening application domains,particularly within the realms of medical intervention and hazardous environments.With the continuous progression of technology,the integration of human intelligence and robotic capabilities is expected to produce more innovations and breakthroughs in the field of automatic control.展开更多
Purpose–This study aims to propose a novel identification method to accurately estimate linear and nonlinear dynamics in permanent magnet synchronous linear motor(PMSLM)based on the time-domain analysis of relay feed...Purpose–This study aims to propose a novel identification method to accurately estimate linear and nonlinear dynamics in permanent magnet synchronous linear motor(PMSLM)based on the time-domain analysis of relay feedback.Design/methodology/approach–A mathematical model of the PMSLM-based servo-mechanical system was first established,incorporating the aforementioned nonlinearities.The model’s velocity response was derived by analyzing its behavior as a first-order system under arbitrary input.To induce oscillatory dynamics,an ideal relay with artificially introduced dead-time components was then integrated into the servo-mechanism.Depending on the oscillations and the time-domain analysis,nonlinear formulas were deduced according to the velocity response of the servo-mechanism.Afterwards,the unknown model parameters can be solved on account of the cost function which utilizes the discrepancy between nominal position characteristics and temporary position characteristics,both of which are extracted from the oscillations.The proposed recognition method was validated through a twostage process:(1)numerical simulation and calculation,followed by(2)real-time experimental verification on a direct-drive servo platform.Subsequently,leveraging the identification results,a novel control strategy was developed and its tracking performance was benchmarked against conventional control schemes.Findings–Simulation results demonstrate that the proposed method achieves estimation accuracy within 8%.Building on this,a novel control strategy is developed by incorporating both friction pulsation and force pulsation identification results into the feedforward compensator.Comparative experiments reveal that this strategy significantly enhances tracking and positioning performance over traditional control schemes.In a word,this new identification method can be used in different process control and servo control systems.Moreover,parameter auto-tuning,feed forward compensation or disturbance observer can be investigated based on the obtained information to improve the system stability and control accuracy.Originality/value–It is of great significance for the performance improvement of rail transit motor control equipment,such as electro-mechanical braking systems.By enhancing the efficiency of motor control,the performance of the product will be more outstanding.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
Force feedback dataglove is an important interface of human-machine interaction between manipulator and virtual assembly system, which is in charge of the bidirectional transmission of movement and force information b...Force feedback dataglove is an important interface of human-machine interaction between manipulator and virtual assembly system, which is in charge of the bidirectional transmission of movement and force information between computer and operator. The exoskeleton force feedback dataglove is designed taking the pneumatic artificial muscle as actuator, meanwhile, its structure and work principle are introduced, and the force control problem is analyzed and researched by experiment. The mathematic model of grasping rigid object for finger is established. Considering the friction of tendon-sheath system and finger deformation, the closed-loop force control for a single joint, a single finger and multi-fingers are studied respectively by the feedforward proportional-integral（PI） control method with variable arguments. On the premise of the force smoothness, the control error of the force exerted on the finger joint is in the range of ±0.25 N, which meets the requirement of force feedback. By experimental analysis, the reason of force fluctuation is that the finger joint has a small amplitude quiver, and the consistent change tendency of the force between proximal interphalangeal（PIP） joint and distal interphalangeal（DIP） joint results from their angle coupling relationship.展开更多
A virtual interventional surgical system with force feedback is designed to provide practice before complicated interventional operation and assistance during operation.The collision detection,vessel deformation calcu...A virtual interventional surgical system with force feedback is designed to provide practice before complicated interventional operation and assistance during operation.The collision detection,vessel deformation calculating and virtual force computing of the virtual system are implemented by using skeleton spring model as the physical modeling foundation,which is based on the mass spring model and easy to construct with high computing efficiency.In order to increase the real time performance,the central plane of the vessel model is extracted and then simplified to complete the skeleton filling.The initiative bending kinematics of the virtual catheter is analyzed so as to provide the virtual system with higher fidelity.The experimental results show that the virtual system can well simulate the vessel deformation and force feedback within an interventional surgery,which gives the virtual system better immersion.展开更多
Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that t...Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.展开更多
An exoskeleton force feedback dataglove is developed,which uses the pneumatic artificial muscles as actuators.On the basis of the simplified hand model,the motion equation is deduced according to the theory of Denavit...An exoskeleton force feedback dataglove is developed,which uses the pneumatic artificial muscles as actuators.On the basis of the simplified hand model,the motion equation is deduced according to the theory of Denavit-Hartenberg.The model of the equivalent contact forces exerted by the object on the finger is proposed.By the principle of virtual work,the static equilibrium of finger is established.The force Jacobian matrix of finger is calculated,and then the joint torques of the finger when grasping objects are obtained.The theory and structure of the force feedback datagolve are introduced.Based on the theory of motion stabilization of four-bar linkage,the flexion angles of joints are measured.The torques on finger joints caused by the output forces of pneumatic artificial muscles are calculated.The output forces of pneumatic artificial muscle,whose values are controlled by its inner pressure,can be calculated by the joint torques of the finger when grasping objects.The arms of force,driving torques and the needed output forces of pneumatic muscle are calculated for each joint of the index finger.The criterion of output force of pneumatic muscle is given.展开更多
Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control alg...Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control algorithm adopted by them was integral force feedback. This paper presents a new proportional-integral （PI） force feedback algorithm to achieve larger damping ratios for the structure without the requirement of structure model. Stability of the control system is shown, and simulations of a structure similar to JPL-MPI demonstrate the effectiveness of the proposed algorithm for vibration control of space structures.展开更多
In this paper,a fifth-order fully differential interface circuit( IC) is presented to improve the noise performance for micromechanical sigma-delta( Σ-Δ) accelerometer. A lead compensator is adopted to ensure the st...In this paper,a fifth-order fully differential interface circuit( IC) is presented to improve the noise performance for micromechanical sigma-delta( Σ-Δ) accelerometer. A lead compensator is adopted to ensure the stability of the closed-loop high-order system. A low noise capacitance detection circuit is described with a correlated-double-sampling( CDS) technique to decrease 1 /f noise and offset of the operational amplifier. This paper also proposes a self-test technique for the interface circuit to test the harmonic distortion. An electrostatic force feedback linearization circuit is presented to reduce the harmonic distortion resulting in larger dynamic range( DR). The layout of the IC is implemented in a standard 0. 6 μm CMOS technology and operates at a sampling frequency of 250 kHz. The interface consumes 20 mW from a 5 V supply. The post-simulation results indicate that the noise floor of the digital accelerometer is about- 140 dBV /Hz1 /2at low frequency. The sensitivity is 2. 5 V /g and the nonlinearity is 0. 11%. The self-test function is achieved with 98. 2 dB thirdorder harmonic distortion detection based on the electrostatic force feedback linearization.展开更多
In this paper, we deal with a remote robot system in which a user can operate an industrial robot with a force sensor at a remote location by using a haptic interface device. We apply a method using the wave filter to...In this paper, we deal with a remote robot system in which a user can operate an industrial robot with a force sensor at a remote location by using a haptic interface device. We apply a method using the wave filter together with the phase control filter which was previously proposed by the authors to the remote robot system for stabilization control. We also propose a method to enhance the haptic quality. By experiment, we demonstrate the effectiveness of the proposed method. We compare the proposed method with the conventional method quantitatively and clarify which domains the proposed method is applied to more effectively.展开更多
Teleoperation systems allow the extension of human capabilities to remote-control devices by providing the operator with conditions similar to those at the remote site through a communication channel that sends inform...Teleoperation systems allow the extension of human capabilities to remote-control devices by providing the operator with conditions similar to those at the remote site through a communication channel that sends information from one site to the other. This article aims to present an analysis of the benefits of force feedback applied to the bilateral teleoperation of a humanoid robot with timevarying delay. As a control scheme, we link adaptive inverse dynamics compensation, balance control, and P+d like controllers. Finally,a test is performed where an operator simultaneously handles the locomotion(forward velocity and turn angle) and arm of a simulated 3D humanoid robot to do a pick-and-place task using two master devices with force feedback, where indexes such as time to complete the task, coordination errors, path tracking error, and percentage of successful tests are reported for different time-delays. We conclude with the results achieved.展开更多
This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface ...This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface device while observing work of the robot with a video camera. We also investigate the effect of the proposed control by experiment. As cooperative work, we deal with work in which two robots carry an object together. The robot position control using force information finely adjusts the position of the robot arm to reduce the force applied to the object. Thus, the purpose of the control is to avoid large force so that the object is not broken. In our experiment, we make a comparison among the following three cases in order to clarify how to carry out the control effectively. In the first case, the two robots are operated manually by a user with his/her both hands. In the second case, one robot is operated manually by a user, and the other robot is moved automatically under the proposed control. In the last case, the object is carried directly by a human instead of the robot which is operated by the user in the second case. As a result, experimental results demonstrate that the control can help each system operated manually by the user to carry the object smoothly.展开更多
This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, ...This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, the thermal boundary layer and its thickness are quantitatively visualized and measured using a Mach-Zehnder interferometer. In addition, the variation in the local heat transfer coefficient is evaluated experimentally with respect to the air flow velocity and temperature. Differences within the heat transfer performance between the plates are confirmed and discussed. As a result, the average heat transfer performance is about the same for the heated plate and the cooled plate under all air velocity conditions. This contrasts with the theoretical prediction in the case of low air velocity, the reason considered was that the buoyancy at the 30° leading edge blocked air from flowing across the surface of the plate.展开更多
A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external struc...A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical （3RPS） parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.展开更多
Background A virtual system that simulates the complete process of orthodontic bracket placement can be used for pre-clinical skill training to help students gain confidence by performing the required tasks on a virtu...Background A virtual system that simulates the complete process of orthodontic bracket placement can be used for pre-clinical skill training to help students gain confidence by performing the required tasks on a virtual patient.Methods The hardware for the virtual simulation system is built using two force feedback devices to support bi-manual force feedback operation.A 3D mouse is used to adjust the position of the virtual patient.A multi-threaded computational methodology is adopted to satisfy the requirements of the frame rate.The computation threads mainly consist of the haptic thread running at a frequency of>1000Hz and the graphic thread at>30Hz.The graphic thread allows the graphics engine to effectively display the visual effects of biofilm removal and acid erosion through texture mapping.Using the haptic thread,the physics engine adopts the hierarchy octree collision-detection algorithm to simulate the multi-point and multi-region interaction between the tools and the virtual environment.Its high efficiency guarantees that the time cost can be controlled within 1 ms.The physics engine also performs collision detection between the tools and particles,making it possible to simulate paint and removal of colloids.The surface-contact constraints are defined in the system;this ensures that the bracket will not divorce from or embed into the tooth during the adjustment of the bracket.Therefore,the simulated adjustment is more realistic and natural.Results A virtual system to simulate the complete process of orthodontic bracket bonding was developed.In addition to bracket bonding and adjustment,the system simulates the necessary auxiliary steps such as smearing,acid etching,and washing.Furthermore,the system supports personalized case training.Conclusions The system provides a new method for students to practice orthodontic skills.展开更多
Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldo...Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldom achieved. Being compliant to external unperceived impacts is cru- cial since it is unavoidable that the slip, modeling errors and imprecise information of terrain will make planned trajectories to be followed with errors and unpredictable contacts. The impedance control gives an inspiration to realize an active compliance which allows the legged robots to follow reference trajectories and overcome external disturbances. In this paper, a novel impedance force/ position control scheme is presented, which is based on Cartesian force measurement of leg＇ s end effector for our hydraulic quadruped robot The simulation verifies the efficiency of the impedance model, and the experimental results at the end demonstrate the feasibility of the proposed control scheme.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
The tele-operation robotic system which consists of an excavator as the construction robot,and two joysticks for operating the robot from a safe place are useful for performing restoration in damaged areas.In order to...The tele-operation robotic system which consists of an excavator as the construction robot,and two joysticks for operating the robot from a safe place are useful for performing restoration in damaged areas.In order to accomplish a precise task,the operator needs to feel a realistic sense of task force brought about from a feedback force between the fork glove of slave robot and unfamiliar environment.A novel force feedback model is proposed based on velocity control of cylinder to determine environment force acting on fork glove.Namely,the feedback force is formed by the error of displacement of joystick with velocity and driving force of piston,and the gain is calculated by the driving force and threshold of driving force of hydraulic cylinder.Moreover,the variable gain improved algorithm is developed to overcome the defect for grasping soft object.Experimental results for fork glove freedom of robotic system are provided to demonstrate the developed algorithm is available for grasping soft object.展开更多
The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs an...The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs and robotic manipulators. A joystick-type device can directly translate various tongue motions to external equipment behavior. In addition, the user can interactively communicate with the equipment by tactile feedback. This helps the user to control the equipment safely and skillfully. Considering these factors, in a previous study [1], we developed a novel tongue-operated joystick device with reaction force feedback mechanism. We described the design process including the analysis of human tongue movement and tactile sensations and showed fundamental performances of reaction force feedback with the prototype device. In this study, we discuss the shape of the operational part that is used by the tongue. Two types of operational tools are prepared and their operability and perception of reaction force feedback are compared. Furthermore, we confirm the effectiveness of reaction force feedback to operate the joystick device safely and skillful controlling a mobile robot in an unknown environment.展开更多
基金supported by the MSIT(Ministry of Science and ICT),Republic of Korea,under the Convergence Security Core Talent Training Business Support Program(IITP-2024-RS-2024-00423071)supervised by the IITP(Institute of Information&Communications Technology Planning&Evaluation)supported by Sichuan Science and Technology Program(2023YFSY0026,2023YFH0004).
文摘Force feedback bilateral teleoperation represents a pivotal advancement in control technology,finding widespread application in hazardous material transportation,perilous environments,space and deep-sea exploration,and healthcare domains.This paper traces the evolutionary trajectory of force feedback bilateral teleoperation from its conceptual inception to its current complexity.It elucidates the fundamental principles underpinning interaction forces and tactile exchanges,with a specific emphasis on the crucial role of tactile devices.In this review,a quantitative analysis of force feedback bilateral teleoperation development trends from 2011 to 2024 has been conducted,utilizing published journal article data as the primary source of information.The review accentuates classical control frameworks and algorithms,while also delving into existing research advancements and prospec-tive breakthrough directions.Moreover,it explores specific practical scenarios ranging from intricate surgeries to hazardous environment exploration,underscoring the technology’s potential to revolutionize industries by augmenting human manipulation of remote systems.This underscores the pivotal role of force feedback bilateral teleoperation as a transformative human-machine interface,capable of shaping flexible control strategies and addressing technological bottlenecks.Future research endeavors in force feedback bilateral teleoperation are expected to prioritize the creation of more immersive experiences,overcoming technical hurdles,fortifying human-machine collaboration,and broadening application domains,particularly within the realms of medical intervention and hazardous environments.With the continuous progression of technology,the integration of human intelligence and robotic capabilities is expected to produce more innovations and breakthroughs in the field of automatic control.
文摘Purpose–This study aims to propose a novel identification method to accurately estimate linear and nonlinear dynamics in permanent magnet synchronous linear motor(PMSLM)based on the time-domain analysis of relay feedback.Design/methodology/approach–A mathematical model of the PMSLM-based servo-mechanical system was first established,incorporating the aforementioned nonlinearities.The model’s velocity response was derived by analyzing its behavior as a first-order system under arbitrary input.To induce oscillatory dynamics,an ideal relay with artificially introduced dead-time components was then integrated into the servo-mechanism.Depending on the oscillations and the time-domain analysis,nonlinear formulas were deduced according to the velocity response of the servo-mechanism.Afterwards,the unknown model parameters can be solved on account of the cost function which utilizes the discrepancy between nominal position characteristics and temporary position characteristics,both of which are extracted from the oscillations.The proposed recognition method was validated through a twostage process:(1)numerical simulation and calculation,followed by(2)real-time experimental verification on a direct-drive servo platform.Subsequently,leveraging the identification results,a novel control strategy was developed and its tracking performance was benchmarked against conventional control schemes.Findings–Simulation results demonstrate that the proposed method achieves estimation accuracy within 8%.Building on this,a novel control strategy is developed by incorporating both friction pulsation and force pulsation identification results into the feedforward compensator.Comparative experiments reveal that this strategy significantly enhances tracking and positioning performance over traditional control schemes.In a word,this new identification method can be used in different process control and servo control systems.Moreover,parameter auto-tuning,feed forward compensation or disturbance observer can be investigated based on the obtained information to improve the system stability and control accuracy.Originality/value–It is of great significance for the performance improvement of rail transit motor control equipment,such as electro-mechanical braking systems.By enhancing the efficiency of motor control,the performance of the product will be more outstanding.
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. 50375034)Research Foundation for the Doctoral Program of Higher Education of China (Grant No. 200802881002)
文摘Force feedback dataglove is an important interface of human-machine interaction between manipulator and virtual assembly system, which is in charge of the bidirectional transmission of movement and force information between computer and operator. The exoskeleton force feedback dataglove is designed taking the pneumatic artificial muscle as actuator, meanwhile, its structure and work principle are introduced, and the force control problem is analyzed and researched by experiment. The mathematic model of grasping rigid object for finger is established. Considering the friction of tendon-sheath system and finger deformation, the closed-loop force control for a single joint, a single finger and multi-fingers are studied respectively by the feedforward proportional-integral（PI） control method with variable arguments. On the premise of the force smoothness, the control error of the force exerted on the finger joint is in the range of ±0.25 N, which meets the requirement of force feedback. By experimental analysis, the reason of force fluctuation is that the finger joint has a small amplitude quiver, and the consistent change tendency of the force between proximal interphalangeal（PIP） joint and distal interphalangeal（DIP） joint results from their angle coupling relationship.
基金supported by National High Technology Development Program of China(No. 51575256)
文摘A virtual interventional surgical system with force feedback is designed to provide practice before complicated interventional operation and assistance during operation.The collision detection,vessel deformation calculating and virtual force computing of the virtual system are implemented by using skeleton spring model as the physical modeling foundation,which is based on the mass spring model and easy to construct with high computing efficiency.In order to increase the real time performance,the central plane of the vessel model is extracted and then simplified to complete the skeleton filling.The initiative bending kinematics of the virtual catheter is analyzed so as to provide the virtual system with higher fidelity.The experimental results show that the virtual system can well simulate the vessel deformation and force feedback within an interventional surgery,which gives the virtual system better immersion.
基金Supported by National Natural Science Foundation of China(51475418)National Basic Research 973 Program of China(2011CB706503)Science Fund for Creative Research Groups of National Natural Science Foundation of China(51221004)
文摘Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.
基金This project is supported by National Natural Science Foundation of China(No.50375034).
文摘An exoskeleton force feedback dataglove is developed,which uses the pneumatic artificial muscles as actuators.On the basis of the simplified hand model,the motion equation is deduced according to the theory of Denavit-Hartenberg.The model of the equivalent contact forces exerted by the object on the finger is proposed.By the principle of virtual work,the static equilibrium of finger is established.The force Jacobian matrix of finger is calculated,and then the joint torques of the finger when grasping objects are obtained.The theory and structure of the force feedback datagolve are introduced.Based on the theory of motion stabilization of four-bar linkage,the flexion angles of joints are measured.The torques on finger joints caused by the output forces of pneumatic artificial muscles are calculated.The output forces of pneumatic artificial muscle,whose values are controlled by its inner pressure,can be calculated by the joint torques of the finger when grasping objects.The arms of force,driving torques and the needed output forces of pneumatic muscle are calculated for each joint of the index finger.The criterion of output force of pneumatic muscle is given.
基金the National Natural Science Foundation of China (10572070)Tsinghua Basic Research Foundation (JCqn2005029)
文摘Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control algorithm adopted by them was integral force feedback. This paper presents a new proportional-integral （PI） force feedback algorithm to achieve larger damping ratios for the structure without the requirement of structure model. Stability of the control system is shown, and simulations of a structure similar to JPL-MPI demonstrate the effectiveness of the proposed algorithm for vibration control of space structures.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61204121)the National Hi-Tech Research and Development Program of China(Grant No.2013AA041107)
文摘In this paper,a fifth-order fully differential interface circuit( IC) is presented to improve the noise performance for micromechanical sigma-delta( Σ-Δ) accelerometer. A lead compensator is adopted to ensure the stability of the closed-loop high-order system. A low noise capacitance detection circuit is described with a correlated-double-sampling( CDS) technique to decrease 1 /f noise and offset of the operational amplifier. This paper also proposes a self-test technique for the interface circuit to test the harmonic distortion. An electrostatic force feedback linearization circuit is presented to reduce the harmonic distortion resulting in larger dynamic range( DR). The layout of the IC is implemented in a standard 0. 6 μm CMOS technology and operates at a sampling frequency of 250 kHz. The interface consumes 20 mW from a 5 V supply. The post-simulation results indicate that the noise floor of the digital accelerometer is about- 140 dBV /Hz1 /2at low frequency. The sensitivity is 2. 5 V /g and the nonlinearity is 0. 11%. The self-test function is achieved with 98. 2 dB thirdorder harmonic distortion detection based on the electrostatic force feedback linearization.
文摘In this paper, we deal with a remote robot system in which a user can operate an industrial robot with a force sensor at a remote location by using a haptic interface device. We apply a method using the wave filter together with the phase control filter which was previously proposed by the authors to the remote robot system for stabilization control. We also propose a method to enhance the haptic quality. By experiment, we demonstrate the effectiveness of the proposed method. We compare the proposed method with the conventional method quantitatively and clarify which domains the proposed method is applied to more effectively.
文摘Teleoperation systems allow the extension of human capabilities to remote-control devices by providing the operator with conditions similar to those at the remote site through a communication channel that sends information from one site to the other. This article aims to present an analysis of the benefits of force feedback applied to the bilateral teleoperation of a humanoid robot with timevarying delay. As a control scheme, we link adaptive inverse dynamics compensation, balance control, and P+d like controllers. Finally,a test is performed where an operator simultaneously handles the locomotion(forward velocity and turn angle) and arm of a simulated 3D humanoid robot to do a pick-and-place task using two master devices with force feedback, where indexes such as time to complete the task, coordination errors, path tracking error, and percentage of successful tests are reported for different time-delays. We conclude with the results achieved.
文摘This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface device while observing work of the robot with a video camera. We also investigate the effect of the proposed control by experiment. As cooperative work, we deal with work in which two robots carry an object together. The robot position control using force information finely adjusts the position of the robot arm to reduce the force applied to the object. Thus, the purpose of the control is to avoid large force so that the object is not broken. In our experiment, we make a comparison among the following three cases in order to clarify how to carry out the control effectively. In the first case, the two robots are operated manually by a user with his/her both hands. In the second case, one robot is operated manually by a user, and the other robot is moved automatically under the proposed control. In the last case, the object is carried directly by a human instead of the robot which is operated by the user in the second case. As a result, experimental results demonstrate that the control can help each system operated manually by the user to carry the object smoothly.
文摘This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, the thermal boundary layer and its thickness are quantitatively visualized and measured using a Mach-Zehnder interferometer. In addition, the variation in the local heat transfer coefficient is evaluated experimentally with respect to the air flow velocity and temperature. Differences within the heat transfer performance between the plates are confirmed and discussed. As a result, the average heat transfer performance is about the same for the heated plate and the cooled plate under all air velocity conditions. This contrasts with the theoretical prediction in the case of low air velocity, the reason considered was that the buoyancy at the 30° leading edge blocked air from flowing across the surface of the plate.
基金National Natural Science Foundation of China(No.50305035)
文摘A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical （3RPS） parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.
文摘Background A virtual system that simulates the complete process of orthodontic bracket placement can be used for pre-clinical skill training to help students gain confidence by performing the required tasks on a virtual patient.Methods The hardware for the virtual simulation system is built using two force feedback devices to support bi-manual force feedback operation.A 3D mouse is used to adjust the position of the virtual patient.A multi-threaded computational methodology is adopted to satisfy the requirements of the frame rate.The computation threads mainly consist of the haptic thread running at a frequency of>1000Hz and the graphic thread at>30Hz.The graphic thread allows the graphics engine to effectively display the visual effects of biofilm removal and acid erosion through texture mapping.Using the haptic thread,the physics engine adopts the hierarchy octree collision-detection algorithm to simulate the multi-point and multi-region interaction between the tools and the virtual environment.Its high efficiency guarantees that the time cost can be controlled within 1 ms.The physics engine also performs collision detection between the tools and particles,making it possible to simulate paint and removal of colloids.The surface-contact constraints are defined in the system;this ensures that the bracket will not divorce from or embed into the tooth during the adjustment of the bracket.Therefore,the simulated adjustment is more realistic and natural.Results A virtual system to simulate the complete process of orthodontic bracket bonding was developed.In addition to bracket bonding and adjustment,the system simulates the necessary auxiliary steps such as smearing,acid etching,and washing.Furthermore,the system supports personalized case training.Conclusions The system provides a new method for students to practice orthodontic skills.
基金Supported by the National High Technology Research and Development Program of China(863Program)(2011AA041002)
文摘Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldom achieved. Being compliant to external unperceived impacts is cru- cial since it is unavoidable that the slip, modeling errors and imprecise information of terrain will make planned trajectories to be followed with errors and unpredictable contacts. The impedance control gives an inspiration to realize an active compliance which allows the legged robots to follow reference trajectories and overcome external disturbances. In this paper, a novel impedance force/ position control scheme is presented, which is based on Cartesian force measurement of leg＇ s end effector for our hydraulic quadruped robot The simulation verifies the efficiency of the impedance model, and the experimental results at the end demonstrate the feasibility of the proposed control scheme.
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 National Natural Science Foundation of China(No.50475011).
文摘The tele-operation robotic system which consists of an excavator as the construction robot,and two joysticks for operating the robot from a safe place are useful for performing restoration in damaged areas.In order to accomplish a precise task,the operator needs to feel a realistic sense of task force brought about from a feedback force between the fork glove of slave robot and unfamiliar environment.A novel force feedback model is proposed based on velocity control of cylinder to determine environment force acting on fork glove.Namely,the feedback force is formed by the error of displacement of joystick with velocity and driving force of piston,and the gain is calculated by the driving force and threshold of driving force of hydraulic cylinder.Moreover,the variable gain improved algorithm is developed to overcome the defect for grasping soft object.Experimental results for fork glove freedom of robotic system are provided to demonstrate the developed algorithm is available for grasping soft object.
文摘The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs and robotic manipulators. A joystick-type device can directly translate various tongue motions to external equipment behavior. In addition, the user can interactively communicate with the equipment by tactile feedback. This helps the user to control the equipment safely and skillfully. Considering these factors, in a previous study [1], we developed a novel tongue-operated joystick device with reaction force feedback mechanism. We described the design process including the analysis of human tongue movement and tactile sensations and showed fundamental performances of reaction force feedback with the prototype device. In this study, we discuss the shape of the operational part that is used by the tongue. Two types of operational tools are prepared and their operability and perception of reaction force feedback are compared. Furthermore, we confirm the effectiveness of reaction force feedback to operate the joystick device safely and skillful controlling a mobile robot in an unknown environment.
