Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexter...Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexterous design per the requirements of anthropomorphic robots. Underactuated self-adaptive theory is adopted to decrease the number of motors and weight. The fingers of HIT ARhand with multi phalanges have the same size as those of an adult hand. Force control is realized with the position sensor, joint torque sensor and fingertip torque sensor. From the 3D model, the whole hand, with the low power consumption DSP control board integrated in it, will weigh only 500 g. It will be assembled on a BIT-Anthropomorphic Robot.展开更多
The forward design of trajectory planning strategies requires preset trajectory optimization functions,resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajecto...The forward design of trajectory planning strategies requires preset trajectory optimization functions,resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajectories that conform to real driver behavior habits.In addition,owing to the strong time-varying dynamic characteristics of obstacle avoidance scenarios,it is necessary to design numerous trajectory optimization functions and adjust the corresponding parameters.Therefore,an anthropomorphic obstacle-avoidance trajectory planning strategy for adaptive driving scenarios is proposed.First,numerous expert-demonstrated trajectories are extracted from the HighD natural driving dataset.Subsequently,a trajectory expectation feature-matching algorithm is proposed that uses maximum entropy inverse reinforcement learning theory to learn the extracted expert-demonstrated trajectories and achieve automatic acquisition of the optimization function of the expert-demonstrated trajectory.Furthermore,a mapping model is constructed by combining the key driving scenario information that affects vehicle obstacle avoidance with the weight of the optimization function,and an anthropomorphic obstacle avoidance trajectory planning strategy for adaptive driving scenarios is proposed.Finally,the proposed strategy is verified based on real driving scenarios.The results show that the strategy can adjust the weight distribution of the trajectory optimization function in real time according to the“emergency degree”of obstacle avoidance and the state of the vehicle.Moreover,this strategy can generate anthropomorphic trajectories that are similar to expert-demonstrated trajectories,effectively improving the adaptability and acceptability of trajectories in driving scenarios.展开更多
This paper deals with the mechanics problem of dynamic walking of anthropomorphic biped robots. Through analysing the mechanics system of this kind of robots in detail, the motion constraint equations are established,...This paper deals with the mechanics problem of dynamic walking of anthropomorphic biped robots. Through analysing the mechanics system of this kind of robots in detail, the motion constraint equations are established, three mechanics laws describing the r展开更多
This paper presents a new developed anthropomorphic robot dexterous hand： HIT/DLR Hand II. The hand is composed of an independent palm and five identical modular fingers, and each finger has three degree of freedom ...This paper presents a new developed anthropomorphic robot dexterous hand： HIT/DLR Hand II. The hand is composed of an independent palm and five identical modular fingers, and each finger has three degree of freedom （DOFs） and four joints. All the actuators and electronics are integrated in the finger body and the palm. Owing to using a new actuator, drivers and a novel arrangement, both the length and width of the finger is about two third of its formner version. By using the wire coupling mecha- nism, the distal phalanx transmission ratio is kept exactly 1 ： 1 in the whole movement range. The packing mechanism which is implemented directly in the finger body and palm not only reduces the size of whole hand but also make it more anthropomorphic. Additionally, the new designed force/torque and position sensors are integrated in the hand for increasing muhisensory capability. To evaluate the performances of the finger mechanism, the position and impedance control experiments are conducted.展开更多
This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output...This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output forces,high efficiency,compactness,inherent compliance,and the ability to transmit power over distances.However,conventional sensors used in TSA-actuated robotic hands increase stiffness,mass,volume,and complexity,making feedback control challenging.To address this issue,a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite(CPC).By measuring the resistance changes in the strain-sensing string,the bending angle of the robot hand's fingers can be estimated,enabling closed-loop control without external sensors.The developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers,a palm,five self-sensing TSAs,and a 3D-printed forearm.Experimental studies validate the self-sensing properties of the TSA and the anthropomorphic robot hand.Additionally,a real-time Virtual Reality(VR)monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing capabilities.This research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.展开更多
Designing anthropomorphic prosthetic hands that approach human-level performance remains a great challenge.Commercial prosthetics are still inferior to human hands in several important properties, such as weight, size...Designing anthropomorphic prosthetic hands that approach human-level performance remains a great challenge.Commercial prosthetics are still inferior to human hands in several important properties, such as weight, size, fingertip force,grasp velocity, and active and passive dexterities. We present a novel design based on the under-actuated da Vinci’s mechanism driven by a flexible twisted string actuator(TSA). The distributed drive scheme allows structural optimization using a motion capture database to reproduce the natural movement of human hands while keeping adaptability to free-form objects. The application of TSA realizes a high conversion from motor torque to tendon contraction force while keeping the structure light,flexible, and compact. Our anthropomorphic prosthetic hand, consisting of six active and 15 passive degrees of freedom, has a weight of 280 g, approximately 70% of that of a human hand. It passed 30 of the 33 Feix grasp tests on objects in daily living and retained a loading capacity of 5 kg. This simple but intelligent mechanism leads to excellent stability and adaptability and renders feasible wide applications in prosthetics and in service robots.展开更多
The main goal of the work is to increase the accuracy of the anthropomorphic manipulator master⁃slave teleoperation by calculating the coordinates of the operator’s arm joints.The master device is an exoskeleton worn...The main goal of the work is to increase the accuracy of the anthropomorphic manipulator master⁃slave teleoperation by calculating the coordinates of the operator’s arm joints.The master device is an exoskeleton worn on the operator’s arm,and the slave device is an anthropomorphic manipulator.A method based on the solution of the forward kinematics and empirical simplifications is proposed in this paper.The position of the nodal points of the exoskeleton was calculated by solving the direct kinematics problem.The coordinates of the operator’s arm joints,which were rigidly connected to the exoskeleton nodal points,were calculated geometrically.For the operator’s arm elbow joint,which was flexibly connected to the exoskeleton,an empirical relation was proposed.It simplified the calculation of the elbow joint position.The experiment showed a decrease in the mismatch between the operator’s arm angles and the manipulator joint angles from 20.7°to 2.9°.The proposed method increases the convenience of the master⁃slave control.展开更多
The common method classifying tactile qualities of fabrics is indirectly based on their difference of purely mechanical and physical properties. When human skin slides across fabric surfaces, the friction interaction ...The common method classifying tactile qualities of fabrics is indirectly based on their difference of purely mechanical and physical properties. When human skin slides across fabric surfaces, the friction interaction between fabrics and skin will occur and trigger the cutaneouS tactile receptors, which are responsible for perceived tactile sensation. By the extracted features from friction- induced vibration signals, this paper presents an anthropomorphic classification method classifying tactile qualities of fabrics. The friction-induced vibration signals are recorded by a three-axis accelerator sensor, and the entice testing procedure is conducted in an anthropomorphic way to obtain vibration signals. The fast Fourier transform （FFT） is applied to analyzing the recoded signals, and then the classification features are extracted from the FFT data by the neurophysiological properties of tactile receptors. The extracted features are used to classify fabric samples by the softness sensation and the roughness sensation, respectively, and the classification performance is checked by a comparison with those in a sensory evaluation procedure. The results showed that the anthropomorphic objective classification method was precise and efficient to clarify tactile qualities of woven fabrics.展开更多
A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld ar...A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld arm, the real-time selection of a redundant join (R-joint) is done and its equivalent virtual torque is obtained, thus the redundant joint can be controlled with whose force feedback. An inverse kinematics solution of a 6-DOF robot is applied to other six joints of the arm. Simulation experiments indicate the new inverse kinematics solution has perfect collision avoidance effect, and it is well simplified. Therefore, it can be applied to a welding task in complex operation space.展开更多
The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high...The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high performance in terms of gripping possibilities and a very low manufacturing cost. Source of inspiration was the human hand, which is able to catch objects by only using two fingers. The analyzed anthropomorphic gripper has two fingers, with two phalanxes each, and is based on a new mechanism with articulated bars. The kinematic analysis performed on the gripping mechanism reveals the optimal displacement in the translational coupling, which was experimentally validated. The gripping possibilities were increased by attaching clamping jaws to each phalanx. The clamping jaws have been attached by means of spherical couplings, thus offering the possibility to catch objects with any type of surface. By carrying out gripping tests with different objects, we underline the importance of a safe use of the two-fingered anthropomorphic grippers in different applications. Due to the innovative mechanical structure, the gripper can insure the minimal gripping conditions, whilst the complexity of the objects that can be gripped make it suitable for the use in robots.展开更多
The underactuated fingers used in prosthetic hands account for a large part of design consideration in anthropomorphic prosthetic hand design.There are considerable numbers of designs available for underactuated prost...The underactuated fingers used in prosthetic hands account for a large part of design consideration in anthropomorphic prosthetic hand design.There are considerable numbers of designs available for underactuated prosthetic fingers in literature but,emulating the anthropomorphic flexion movement is still a challenge due to the complex nature of the motion.To address this challenge,a hybrid mechanism using both linkage-based mechanism and tendon-driven actuation has been proposed in this paper.The presented mechanism includes a novel offset slider-crank-based finger that has been designed using a combination of different lengths of cranks and connecting rods.The prototypes of both the new mechanism and the conventional tendon-driven mechanism are constructed and compared experimentally based on interphalangeal joint angle trajectory during flexion.The angles achieved through the new hybrid mechanism are compared with the conventional tendon-driven mechanism and the Root Mean Square Error(RMSE)values have been calculated by comparing to the anthropomorphic flexion angles of the published literature.The RMSE values calculated for three interphalangeal joints of the hybrid mechanism are found to be less than their counter-parts of the conventional tendon-driven mechanism.In addition to achieving resemblance to anthropomorphic flexion angles,the mechanism is designed within the anthropometric human finger dimensions.展开更多
Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and huma...Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and human body model(HBM)was explored.Methods:Through the ATD model and HBM simulation,the mapping relationship of lumbar injury between the 2 subjects was explored.The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring.Three seatback recline states of 25°,45°,and 65°were designed,and the seat pan angle was maintained at 15°.A 23 g,47 km/h pulse was used.The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results.ATD model was the test device for human occupant restraint for autonomous vehicles(THOR-AV)dummy model and HBM was the total human model for safety(THUMS)v6.1.The posture of the 2 models was adjusted to adapt to the 3 seat states.The lumbar response of THOR-AV and the mechanical and biomechanical data on L1-L5 vertebrae of THUMS were output,and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed.Results:Both THOR-AV and THUMS were submarined in the 65°seatback angle case.With the change of seatback angle,the lumbar spine axial compression force(F_(z))of THOR-AV and THUMS changed in the similar trend.The maximum F_(z) ratio of THOR-AV to THUMS at 25°and 45°seatback angle cases were 1.6 and 1.7.The flexion moment(M_(y))and the time when the maximum M_(y) occurred in the 2 subjects were very different.In particular,the form of moment experienced by the L1-L5 vertebrae of THUMS also changed.The changing trend of M_(y) measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS.Conclusion:The F_(z) of ATD and HBM presents a certain proportional relationship,and there is a mapping relationship between the 2 subjects on F_(z).The mapping function can be further clarified by applying more pulses and adopting more seatback angles.It is difficult to map M_(y) directly because they are very different in ATD and HBM.The M_(y) of ATD and stress of HBM lumbar showed a similar change trend over time,and there may be a hidden mapping relationship.展开更多
As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.I...As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.In pursuit of this,we designed a dedicated 7-degrees-of-freedom(DoF)anthropomorphic robotic arm having three compact differential joints and a head-mounted gaze tracker enabling head-pose-tracked 3D gaze estimation.Moreover,two key challenges were addressed to achieve accurate robot-assisted manipulation of the object indicated by the direction of human gaze.First,a novel predictive pupil feature was proposed for 3D gaze estimation.Differing from most existing features subjected to the common paraxial approximation assumption,the proposed novel predictive pupil feature considered the light refraction at two corneal surfaces with a more realistic eye model,significantly improving the 3D gaze estimation accuracy when the eyeball rotates at large angles.Second,a novel optimization-based approach was developed to efficiently compensate for the posture errors of the designed 7-DoF anthropomorphic robotic arm for accurate manipulation.Compared with the existing Jacobian-based or optimization-based approaches with nominal joint values as iteration initial,the proposed approach computed the optimal iteration initial and realized faster convergence for real-time posture error compensation.With the posture error compensation in real time and 3D gaze estimated accurately,the human can command accurate robot-assisted manipulation using his eyes intuitively.The proposed system was successfully tested on five healthy subjects.展开更多
Humans excel at dexterous manipulation;however,achieving human-level dexterity remains a significant challenge for robots.Technological breakthroughs in the design of anthropomorphic robotic hands,as well as advanceme...Humans excel at dexterous manipulation;however,achieving human-level dexterity remains a significant challenge for robots.Technological breakthroughs in the design of anthropomorphic robotic hands,as well as advancements in visual and tactile perception,have demonstrated significant advantages in addressing this issue.However,coping with the inevitable uncertainty caused by unstructured and dynamic environments in human-like dexterous manipulation tasks,especially for anthropomorphic five-fingered hands,remains an open problem.In this paper,we present a focused review of human-like dexterous manipulation for anthropomorphic five-fingered hands.We begin by defining human-like dexterity and outlining the tasks associated with human-like robot dexterous manipulation.Subsequently,we delve into anthropomorphism and anthropomorphic five-fingered hands,covering definitions,robotic design,and evaluation criteria.Furthermore,we review the learning methods for achieving human-like dexterity in anthropomorphic five-fingered hands,including imitation learning,reinforcement learning and their integration.Finally,we discuss the existing challenges and propose future research directions.This review aims to stimulate interest in scientific research and future applications.展开更多
Prosthetic hands are becoming more and more popular among people without a hand and it is able to perform certain manual operations in function.In biology,action potentials trigger muscle contractions,and surface elec...Prosthetic hands are becoming more and more popular among people without a hand and it is able to perform certain manual operations in function.In biology,action potentials trigger muscle contractions,and surface electromyography（sEMG）signals are the sum of action potentials under the skin exposed by the electrodes（via sebum and solution conduction）.展开更多
文摘Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexterous design per the requirements of anthropomorphic robots. Underactuated self-adaptive theory is adopted to decrease the number of motors and weight. The fingers of HIT ARhand with multi phalanges have the same size as those of an adult hand. Force control is realized with the position sensor, joint torque sensor and fingertip torque sensor. From the 3D model, the whole hand, with the low power consumption DSP control board integrated in it, will weigh only 500 g. It will be assembled on a BIT-Anthropomorphic Robot.
基金supported by the National Natural Science Foundation of China(51875302)。
文摘The forward design of trajectory planning strategies requires preset trajectory optimization functions,resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajectories that conform to real driver behavior habits.In addition,owing to the strong time-varying dynamic characteristics of obstacle avoidance scenarios,it is necessary to design numerous trajectory optimization functions and adjust the corresponding parameters.Therefore,an anthropomorphic obstacle-avoidance trajectory planning strategy for adaptive driving scenarios is proposed.First,numerous expert-demonstrated trajectories are extracted from the HighD natural driving dataset.Subsequently,a trajectory expectation feature-matching algorithm is proposed that uses maximum entropy inverse reinforcement learning theory to learn the extracted expert-demonstrated trajectories and achieve automatic acquisition of the optimization function of the expert-demonstrated trajectory.Furthermore,a mapping model is constructed by combining the key driving scenario information that affects vehicle obstacle avoidance with the weight of the optimization function,and an anthropomorphic obstacle avoidance trajectory planning strategy for adaptive driving scenarios is proposed.Finally,the proposed strategy is verified based on real driving scenarios.The results show that the strategy can adjust the weight distribution of the trajectory optimization function in real time according to the“emergency degree”of obstacle avoidance and the state of the vehicle.Moreover,this strategy can generate anthropomorphic trajectories that are similar to expert-demonstrated trajectories,effectively improving the adaptability and acceptability of trajectories in driving scenarios.
文摘This paper deals with the mechanics problem of dynamic walking of anthropomorphic biped robots. Through analysing the mechanics system of this kind of robots in detail, the motion constraint equations are established, three mechanics laws describing the r
基金supported by the National High Technology Research and Development Programme of China(2006AA04Z255)the 111 Project(B307018)
文摘This paper presents a new developed anthropomorphic robot dexterous hand： HIT/DLR Hand II. The hand is composed of an independent palm and five identical modular fingers, and each finger has three degree of freedom （DOFs） and four joints. All the actuators and electronics are integrated in the finger body and the palm. Owing to using a new actuator, drivers and a novel arrangement, both the length and width of the finger is about two third of its formner version. By using the wire coupling mecha- nism, the distal phalanx transmission ratio is kept exactly 1 ： 1 in the whole movement range. The packing mechanism which is implemented directly in the finger body and palm not only reduces the size of whole hand but also make it more anthropomorphic. Additionally, the new designed force/torque and position sensors are integrated in the hand for increasing muhisensory capability. To evaluate the performances of the finger mechanism, the position and impedance control experiments are conducted.
基金supported by the Anhui Provincial Key Research and Development Program No.2022f04020008National Natural Science Foundation of China No.62301522Anhui Provincial Nature Science Foundation No.1908085MF196.
文摘This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output forces,high efficiency,compactness,inherent compliance,and the ability to transmit power over distances.However,conventional sensors used in TSA-actuated robotic hands increase stiffness,mass,volume,and complexity,making feedback control challenging.To address this issue,a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite(CPC).By measuring the resistance changes in the strain-sensing string,the bending angle of the robot hand's fingers can be estimated,enabling closed-loop control without external sensors.The developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers,a palm,five self-sensing TSAs,and a 3D-printed forearm.Experimental studies validate the self-sensing properties of the TSA and the anthropomorphic robot hand.Additionally,a real-time Virtual Reality(VR)monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing capabilities.This research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.
基金supported partly by the Fund of State Key Laboratory of Fluid Power and Mechatronic Systems (Zhejiang University), China。
文摘Designing anthropomorphic prosthetic hands that approach human-level performance remains a great challenge.Commercial prosthetics are still inferior to human hands in several important properties, such as weight, size, fingertip force,grasp velocity, and active and passive dexterities. We present a novel design based on the under-actuated da Vinci’s mechanism driven by a flexible twisted string actuator(TSA). The distributed drive scheme allows structural optimization using a motion capture database to reproduce the natural movement of human hands while keeping adaptability to free-form objects. The application of TSA realizes a high conversion from motor torque to tendon contraction force while keeping the structure light,flexible, and compact. Our anthropomorphic prosthetic hand, consisting of six active and 15 passive degrees of freedom, has a weight of 280 g, approximately 70% of that of a human hand. It passed 30 of the 33 Feix grasp tests on objects in daily living and retained a loading capacity of 5 kg. This simple but intelligent mechanism leads to excellent stability and adaptability and renders feasible wide applications in prosthetics and in service robots.
基金Sponsored by the Federal Targeted Programme“Priority R&D of the Scientific and Technological Complex of Russia for 2014-2020”(Grant No.RFMEFI57517X0166)the financial support of the Ministry of Education and Science of the Russian Federation.
文摘The main goal of the work is to increase the accuracy of the anthropomorphic manipulator master⁃slave teleoperation by calculating the coordinates of the operator’s arm joints.The master device is an exoskeleton worn on the operator’s arm,and the slave device is an anthropomorphic manipulator.A method based on the solution of the forward kinematics and empirical simplifications is proposed in this paper.The position of the nodal points of the exoskeleton was calculated by solving the direct kinematics problem.The coordinates of the operator’s arm joints,which were rigidly connected to the exoskeleton nodal points,were calculated geometrically.For the operator’s arm elbow joint,which was flexibly connected to the exoskeleton,an empirical relation was proposed.It simplified the calculation of the elbow joint position.The experiment showed a decrease in the mismatch between the operator’s arm angles and the manipulator joint angles from 20.7°to 2.9°.The proposed method increases the convenience of the master⁃slave control.
基金National Natural Science Foundations of China，Natural Science Foundation of Shanghai,China，the Fundamental Research Funds for the Central Universities,China
文摘The common method classifying tactile qualities of fabrics is indirectly based on their difference of purely mechanical and physical properties. When human skin slides across fabric surfaces, the friction interaction between fabrics and skin will occur and trigger the cutaneouS tactile receptors, which are responsible for perceived tactile sensation. By the extracted features from friction- induced vibration signals, this paper presents an anthropomorphic classification method classifying tactile qualities of fabrics. The friction-induced vibration signals are recorded by a three-axis accelerator sensor, and the entice testing procedure is conducted in an anthropomorphic way to obtain vibration signals. The fast Fourier transform （FFT） is applied to analyzing the recoded signals, and then the classification features are extracted from the FFT data by the neurophysiological properties of tactile receptors. The extracted features are used to classify fabric samples by the softness sensation and the roughness sensation, respectively, and the classification performance is checked by a comparison with those in a sensory evaluation procedure. The results showed that the anthropomorphic objective classification method was precise and efficient to clarify tactile qualities of woven fabrics.
文摘A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld arm, the real-time selection of a redundant join (R-joint) is done and its equivalent virtual torque is obtained, thus the redundant joint can be controlled with whose force feedback. An inverse kinematics solution of a 6-DOF robot is applied to other six joints of the arm. Simulation experiments indicate the new inverse kinematics solution has perfect collision avoidance effect, and it is well simplified. Therefore, it can be applied to a welding task in complex operation space.
文摘The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high performance in terms of gripping possibilities and a very low manufacturing cost. Source of inspiration was the human hand, which is able to catch objects by only using two fingers. The analyzed anthropomorphic gripper has two fingers, with two phalanxes each, and is based on a new mechanism with articulated bars. The kinematic analysis performed on the gripping mechanism reveals the optimal displacement in the translational coupling, which was experimentally validated. The gripping possibilities were increased by attaching clamping jaws to each phalanx. The clamping jaws have been attached by means of spherical couplings, thus offering the possibility to catch objects with any type of surface. By carrying out gripping tests with different objects, we underline the importance of a safe use of the two-fingered anthropomorphic grippers in different applications. Due to the innovative mechanical structure, the gripper can insure the minimal gripping conditions, whilst the complexity of the objects that can be gripped make it suitable for the use in robots.
基金funded by Department of Science and Technology,Government of India through grant SP/YO/2019/1598.
文摘The underactuated fingers used in prosthetic hands account for a large part of design consideration in anthropomorphic prosthetic hand design.There are considerable numbers of designs available for underactuated prosthetic fingers in literature but,emulating the anthropomorphic flexion movement is still a challenge due to the complex nature of the motion.To address this challenge,a hybrid mechanism using both linkage-based mechanism and tendon-driven actuation has been proposed in this paper.The presented mechanism includes a novel offset slider-crank-based finger that has been designed using a combination of different lengths of cranks and connecting rods.The prototypes of both the new mechanism and the conventional tendon-driven mechanism are constructed and compared experimentally based on interphalangeal joint angle trajectory during flexion.The angles achieved through the new hybrid mechanism are compared with the conventional tendon-driven mechanism and the Root Mean Square Error(RMSE)values have been calculated by comparing to the anthropomorphic flexion angles of the published literature.The RMSE values calculated for three interphalangeal joints of the hybrid mechanism are found to be less than their counter-parts of the conventional tendon-driven mechanism.In addition to achieving resemblance to anthropomorphic flexion angles,the mechanism is designed within the anthropometric human finger dimensions.
基金supported by the National Natural Science Foundation of China(51621004)the Chongqing Doctor"Through Train"Scientific Research Project(CSTB2023NSCQ-BSX0011,CSTB2024NSCQ-BSX0014)+1 种基金the Natural Science Foundation of Hunan Province(2020JJ4184)Natural Science Foundation of Chongqing(CSTB2024NSCQ-MSX0684).
文摘Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and human body model(HBM)was explored.Methods:Through the ATD model and HBM simulation,the mapping relationship of lumbar injury between the 2 subjects was explored.The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring.Three seatback recline states of 25°,45°,and 65°were designed,and the seat pan angle was maintained at 15°.A 23 g,47 km/h pulse was used.The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results.ATD model was the test device for human occupant restraint for autonomous vehicles(THOR-AV)dummy model and HBM was the total human model for safety(THUMS)v6.1.The posture of the 2 models was adjusted to adapt to the 3 seat states.The lumbar response of THOR-AV and the mechanical and biomechanical data on L1-L5 vertebrae of THUMS were output,and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed.Results:Both THOR-AV and THUMS were submarined in the 65°seatback angle case.With the change of seatback angle,the lumbar spine axial compression force(F_(z))of THOR-AV and THUMS changed in the similar trend.The maximum F_(z) ratio of THOR-AV to THUMS at 25°and 45°seatback angle cases were 1.6 and 1.7.The flexion moment(M_(y))and the time when the maximum M_(y) occurred in the 2 subjects were very different.In particular,the form of moment experienced by the L1-L5 vertebrae of THUMS also changed.The changing trend of M_(y) measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS.Conclusion:The F_(z) of ATD and HBM presents a certain proportional relationship,and there is a mapping relationship between the 2 subjects on F_(z).The mapping function can be further clarified by applying more pulses and adopting more seatback angles.It is difficult to map M_(y) directly because they are very different in ATD and HBM.The M_(y) of ATD and stress of HBM lumbar showed a similar change trend over time,and there may be a hidden mapping relationship.
基金supported by the National Natural Science Foundation of China(Grant Nos.52027806,52435005,92248304,52075191).
文摘As humans and robots work closer together than ever,anthropomorphic robotic arms with intuitive human-robot interaction interfaces have drawn massive attention to improving the quality of robot-assisted manipulation.In pursuit of this,we designed a dedicated 7-degrees-of-freedom(DoF)anthropomorphic robotic arm having three compact differential joints and a head-mounted gaze tracker enabling head-pose-tracked 3D gaze estimation.Moreover,two key challenges were addressed to achieve accurate robot-assisted manipulation of the object indicated by the direction of human gaze.First,a novel predictive pupil feature was proposed for 3D gaze estimation.Differing from most existing features subjected to the common paraxial approximation assumption,the proposed novel predictive pupil feature considered the light refraction at two corneal surfaces with a more realistic eye model,significantly improving the 3D gaze estimation accuracy when the eyeball rotates at large angles.Second,a novel optimization-based approach was developed to efficiently compensate for the posture errors of the designed 7-DoF anthropomorphic robotic arm for accurate manipulation.Compared with the existing Jacobian-based or optimization-based approaches with nominal joint values as iteration initial,the proposed approach computed the optimal iteration initial and realized faster convergence for real-time posture error compensation.With the posture error compensation in real time and 3D gaze estimated accurately,the human can command accurate robot-assisted manipulation using his eyes intuitively.The proposed system was successfully tested on five healthy subjects.
基金supported in part by the National Natural Science Foundation of China(91748131,62006229,and 61771471)in part by Young Scientists Fund of the National Natural Science Foundation of China(62303454)+1 种基金in part by the Strategic Priority Research Program of Chinese Academy of Science(XDB32050106)in part by the InnoHK Project.
文摘Humans excel at dexterous manipulation;however,achieving human-level dexterity remains a significant challenge for robots.Technological breakthroughs in the design of anthropomorphic robotic hands,as well as advancements in visual and tactile perception,have demonstrated significant advantages in addressing this issue.However,coping with the inevitable uncertainty caused by unstructured and dynamic environments in human-like dexterous manipulation tasks,especially for anthropomorphic five-fingered hands,remains an open problem.In this paper,we present a focused review of human-like dexterous manipulation for anthropomorphic five-fingered hands.We begin by defining human-like dexterity and outlining the tasks associated with human-like robot dexterous manipulation.Subsequently,we delve into anthropomorphism and anthropomorphic five-fingered hands,covering definitions,robotic design,and evaluation criteria.Furthermore,we review the learning methods for achieving human-like dexterity in anthropomorphic five-fingered hands,including imitation learning,reinforcement learning and their integration.Finally,we discuss the existing challenges and propose future research directions.This review aims to stimulate interest in scientific research and future applications.
基金supported by the National Natural Science Foundation of China(Grant No.51575020)the National Key Technology R&D Program(Grant No.2015BAI02B00)Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems
文摘Prosthetic hands are becoming more and more popular among people without a hand and it is able to perform certain manual operations in function.In biology,action potentials trigger muscle contractions,and surface electromyography（sEMG）signals are the sum of action potentials under the skin exposed by the electrodes（via sebum and solution conduction）.
