In order to improve the elderly people's quality of life,supporting their walking behaviors is a promising technology.Therefore,based on one ultrasonic motor,a wire-driven series elastic mechanism for walking assi...In order to improve the elderly people's quality of life,supporting their walking behaviors is a promising technology.Therefore,based on one ultrasonic motor,a wire-driven series elastic mechanism for walking assistive system is proposed and investigated in this research.In contrast to tradition,it innovatively utilizes an ultrasonic motor and a wire-driven series elastic mechanism to achieve superior system performances in aspects of simple structure,high torque/weight ratio,quiet operation,quick response,favorable electromagnetic compatibility,strong shock resistance,better safety,and accurately stable force control.The proposed device is mainly composed of an ultrasonic motor,a linear spring,a steel wire,four pulleys and one rotating part.To overcome the ultrasonic motor's insufficient output torque,a steel wire and pulleys are smartly combined to directly magnify the torque instead of using a conventional gear reducer.Among the pulleys,there is one tailored pulley playing an important role to keep the reduction ratio as 4.5 constantly.Meanwhile,the prototype is manufactured and its actual performance is verified by experimental results.In a one-second operating cycle,it only takes 86 ms for this mechanism to output an assistive torque of 1.6 N·m.At this torque,the ultrasonic motor's speed is around 4.1 rad/s.Moreover,experiments with different operation periods have been conducted for different application scenarios.This study provides a useful idea for the application of ultrasonic motor in walking assistance system.展开更多
近年来 ,通过影像学及眼眶的组织学研究证实在眼球赤道部附近有一个由胶原、弹性蛋白和平滑肌构成的 pulley。Pulley作为眼外肌的功能性起点决定着直肌作用力的方向和大小。本文就 pul ley的提出、组织结构、位置及对于非共同性斜视的...近年来 ,通过影像学及眼眶的组织学研究证实在眼球赤道部附近有一个由胶原、弹性蛋白和平滑肌构成的 pulley。Pulley作为眼外肌的功能性起点决定着直肌作用力的方向和大小。本文就 pul ley的提出、组织结构、位置及对于非共同性斜视的意义等作一综述。展开更多
According to the requirements of designing V-groove pulley transmission, an application development based on AutoCAD environment and using AutoLISP language is presented. As an example of effective solution for CAD ap...According to the requirements of designing V-groove pulley transmission, an application development based on AutoCAD environment and using AutoLISP language is presented. As an example of effective solution for CAD application, the CAD system for V-groove pulley transmission is established.展开更多
Due to the small models and compact structures,small harvesters have also caused problems such as poor threshing separation performance and large loss rates.In order to solve unstable cleaning effects of small harvest...Due to the small models and compact structures,small harvesters have also caused problems such as poor threshing separation performance and large loss rates.In order to solve unstable cleaning effects of small harvesters when they facing different working conditions,this study selected rice plants in hilly areas for the experiment.Tensile breaking force of different parts of mature rice was tested,which revealed the fracture mechanism of each part under the combined force.Inertial threshing method was used to simulate artificial plate bin and design three kinds of non-circular pulley variable speed transmission threshing mechanism.With the help of transient inertia force,threshing force was compensated.This paper tested the harvesting performance of the variable speed threshing device with the help of the harvest performance test.Results show when facing the small rice planting area,the T/2 variable speed threshing device has better cleaning performance,and also the harvest loss rate of T/4 variable speed threshing device is the lowest.Compared with the constant speed threshing device,the impurity content rate of the variable speed threshing device is increased by 0.64%to 8.76%;the loss rate is reduced by 0.45%to 1.79%,which provides a basis for the optimization design of small combine harvester in hilly areas.展开更多
Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. How...Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.展开更多
Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients.Most injuries are open injuries to the flexor or extensor tendons,but less frequent in...Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients.Most injuries are open injuries to the flexor or extensor tendons,but less frequent injuries,e.g.,damage to the functional system tendon sheath and pulley or dull avulsions,also need to be considered.After clinical examination,ultrasound and magnetic resonance imaging have proved to be important diagnostic tools.Tendon injuries mostly require surgical repair,dull avulsions of the distal phalanges extensor tendon can receive conservative therapy.Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair.In the postoperative course offlexor tendon injuries,the principle of early passive movement is important to trigger an"intrinsic"tendon healing to guarantee a good outcome.Many substances were evaluated to see if they improved tendon healing;however,little evidence was found.Nevertheless,hyaluronic acid may improve intrinsic tendon healing.展开更多
Taking the MK7-3 of USA hydraulic buffer arresting device as the research subject,the dynamical model for the shipboard aircraft arresting system is established,and the magneto-rheological(MR) damper is applied to pul...Taking the MK7-3 of USA hydraulic buffer arresting device as the research subject,the dynamical model for the shipboard aircraft arresting system is established,and the magneto-rheological(MR) damper is applied to pulley shock absorbers for shipboard aircraft block system.Due to the effect of the MR damper has not been known completely and so far MR damper model has not been defined,we use a set of characteristic test of the MR damper,through the process of parameters identification,to establish the dynamical model for the MR damper based on the Bingham plastic model.Then,the fuzzy control rules are designed,the buffer control for the pulley buffer of shipboard aircrafts is completed in touchdown moment based on MR technology. Compared with blocking device of hydraulic pulley buffer in the same condition,the simulations results show that the proposed MR pulley buffer can effectively recognize the impact energy for shipboard block system and reduce the pull peak of arresting cable.It improves significantly safety during landing of the air vehicles and lowers the risk of accidents.展开更多
Rotary pneumatic actuators that are made out of linear one are always best suited for exoskeleton joint actuation due to its inherent power to weight ratio. This work is a modified version of knee actuation system tha...Rotary pneumatic actuators that are made out of linear one are always best suited for exoskeleton joint actuation due to its inherent power to weight ratio. This work is a modified version of knee actuation system that has already been developed and major modifications are made in order to make it more suitable for human wearing and also to reduce its bulkiness and complexity. The considered actuator system is a rotary actuator where a pulley converts the linear motion of the standard pneumatic piston into the rotary motion. To prove the capability of the actuator, its performance characteristics such as torque and power produced are compared to the required torque and power at the knee joint of the exoskeleton in swing phase and are found to be excellent. The two-way analysis of variance(ANOVA)is performed to find the effect of the throat area valve on knee angle. The ANOVA shows the significant effect of the throat area variation on the knee angle flexion made by the proposed actuator. A relationship between the throat area of flow control valve, that is connected to the exit port of the direction control valve, and angular displacement of the knee joint has been formulated. This relationship can be used to design a control system to regulate the mass flow rate of air at the exit and hence the angular velocity of the knee joint can be controlled.展开更多
The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematic...The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematical model of the V-belt drive was constructed. The power output of the belt drive was modeled and optimized by the Response Surface Methodology (RSM). Analysis of variance was used to evaluate the extent of influence of each independent variables on the power output response of the belt drive. A RSM optimization process was proposed to calculate optimal power output for V-belt drive given a set of pulley diameter for the drive employed in a tilling machine. The analysis showed that optimum power output of the drive for workshop light operation machinery could be obtained at driving and driven pulley radius range of 550 - 900 mm and 250 - 500 mm. An optimum power output of 1418.76 kW was obtained at driving and driven pulley radius of 846 and 486 mm respectively for a farm tilling machine.展开更多
基金Supported by China Scholarship Council(Grant No.202006830033),Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)of China.
文摘In order to improve the elderly people's quality of life,supporting their walking behaviors is a promising technology.Therefore,based on one ultrasonic motor,a wire-driven series elastic mechanism for walking assistive system is proposed and investigated in this research.In contrast to tradition,it innovatively utilizes an ultrasonic motor and a wire-driven series elastic mechanism to achieve superior system performances in aspects of simple structure,high torque/weight ratio,quiet operation,quick response,favorable electromagnetic compatibility,strong shock resistance,better safety,and accurately stable force control.The proposed device is mainly composed of an ultrasonic motor,a linear spring,a steel wire,four pulleys and one rotating part.To overcome the ultrasonic motor's insufficient output torque,a steel wire and pulleys are smartly combined to directly magnify the torque instead of using a conventional gear reducer.Among the pulleys,there is one tailored pulley playing an important role to keep the reduction ratio as 4.5 constantly.Meanwhile,the prototype is manufactured and its actual performance is verified by experimental results.In a one-second operating cycle,it only takes 86 ms for this mechanism to output an assistive torque of 1.6 N·m.At this torque,the ultrasonic motor's speed is around 4.1 rad/s.Moreover,experiments with different operation periods have been conducted for different application scenarios.This study provides a useful idea for the application of ultrasonic motor in walking assistance system.
文摘According to the requirements of designing V-groove pulley transmission, an application development based on AutoCAD environment and using AutoLISP language is presented. As an example of effective solution for CAD application, the CAD system for V-groove pulley transmission is established.
基金the National Natural Science Foundation of China(Grant No.52175235)Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province(Grant No.2023ZJZD2302)+1 种基金Jiangsu Province and Education Ministry Co-sponsored Synergistic Innovation Center of Modern Agricultural Equipment(Grant No.XTCX2007)Taizhou Science and Technology Support Plan(Agriculture)Project(TN202219).
文摘Due to the small models and compact structures,small harvesters have also caused problems such as poor threshing separation performance and large loss rates.In order to solve unstable cleaning effects of small harvesters when they facing different working conditions,this study selected rice plants in hilly areas for the experiment.Tensile breaking force of different parts of mature rice was tested,which revealed the fracture mechanism of each part under the combined force.Inertial threshing method was used to simulate artificial plate bin and design three kinds of non-circular pulley variable speed transmission threshing mechanism.With the help of transient inertia force,threshing force was compensated.This paper tested the harvesting performance of the variable speed threshing device with the help of the harvest performance test.Results show when facing the small rice planting area,the T/2 variable speed threshing device has better cleaning performance,and also the harvest loss rate of T/4 variable speed threshing device is the lowest.Compared with the constant speed threshing device,the impurity content rate of the variable speed threshing device is increased by 0.64%to 8.76%;the loss rate is reduced by 0.45%to 1.79%,which provides a basis for the optimization design of small combine harvester in hilly areas.
基金Supported by Joint Funds of National Natural Science Foundation of China(Grant No.U1613201)Shenzhen Research Funds(JCYJ20170413104438332)
文摘Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.
文摘Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients.Most injuries are open injuries to the flexor or extensor tendons,but less frequent injuries,e.g.,damage to the functional system tendon sheath and pulley or dull avulsions,also need to be considered.After clinical examination,ultrasound and magnetic resonance imaging have proved to be important diagnostic tools.Tendon injuries mostly require surgical repair,dull avulsions of the distal phalanges extensor tendon can receive conservative therapy.Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair.In the postoperative course offlexor tendon injuries,the principle of early passive movement is important to trigger an"intrinsic"tendon healing to guarantee a good outcome.Many substances were evaluated to see if they improved tendon healing;however,little evidence was found.Nevertheless,hyaluronic acid may improve intrinsic tendon healing.
基金the National Natural Science Foundation of China(No.61074090)the Program for Liaoning Excellent Talents in University(No.LR2011005)the Aviation Industry Corporation of China Innovation Funds(No.cxy2011SH)
文摘Taking the MK7-3 of USA hydraulic buffer arresting device as the research subject,the dynamical model for the shipboard aircraft arresting system is established,and the magneto-rheological(MR) damper is applied to pulley shock absorbers for shipboard aircraft block system.Due to the effect of the MR damper has not been known completely and so far MR damper model has not been defined,we use a set of characteristic test of the MR damper,through the process of parameters identification,to establish the dynamical model for the MR damper based on the Bingham plastic model.Then,the fuzzy control rules are designed,the buffer control for the pulley buffer of shipboard aircrafts is completed in touchdown moment based on MR technology. Compared with blocking device of hydraulic pulley buffer in the same condition,the simulations results show that the proposed MR pulley buffer can effectively recognize the impact energy for shipboard block system and reduce the pull peak of arresting cable.It improves significantly safety during landing of the air vehicles and lowers the risk of accidents.
基金supported by the Technical Education Quality Improvement Programme (TEQIP),India (NITC/TEQIP-II/R & d/2014)
文摘Rotary pneumatic actuators that are made out of linear one are always best suited for exoskeleton joint actuation due to its inherent power to weight ratio. This work is a modified version of knee actuation system that has already been developed and major modifications are made in order to make it more suitable for human wearing and also to reduce its bulkiness and complexity. The considered actuator system is a rotary actuator where a pulley converts the linear motion of the standard pneumatic piston into the rotary motion. To prove the capability of the actuator, its performance characteristics such as torque and power produced are compared to the required torque and power at the knee joint of the exoskeleton in swing phase and are found to be excellent. The two-way analysis of variance(ANOVA)is performed to find the effect of the throat area valve on knee angle. The ANOVA shows the significant effect of the throat area variation on the knee angle flexion made by the proposed actuator. A relationship between the throat area of flow control valve, that is connected to the exit port of the direction control valve, and angular displacement of the knee joint has been formulated. This relationship can be used to design a control system to regulate the mass flow rate of air at the exit and hence the angular velocity of the knee joint can be controlled.
文摘The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematical model of the V-belt drive was constructed. The power output of the belt drive was modeled and optimized by the Response Surface Methodology (RSM). Analysis of variance was used to evaluate the extent of influence of each independent variables on the power output response of the belt drive. A RSM optimization process was proposed to calculate optimal power output for V-belt drive given a set of pulley diameter for the drive employed in a tilling machine. The analysis showed that optimum power output of the drive for workshop light operation machinery could be obtained at driving and driven pulley radius range of 550 - 900 mm and 250 - 500 mm. An optimum power output of 1418.76 kW was obtained at driving and driven pulley radius of 846 and 486 mm respectively for a farm tilling machine.