The application of soft pneumatic actuators is typically hindered by the low strength and slow response speed caused by their intrinsic material limitation and unstressed stable form.In this work,we present a design s...The application of soft pneumatic actuators is typically hindered by the low strength and slow response speed caused by their intrinsic material limitation and unstressed stable form.In this work,we present a design strategy for improving the performance and response speed for Pneu-Nets actuators by incorporating adjustable elastic components to form the elastic composite pneumatic actuator(ECPA).The elastic energy storage of the elastic component is implemented to enhance the capability and speed up the response of ECPA and pre-bend the actuator.Due to the design principle,the fully-flexible ECPA is easy to manufacture and regulate.Theoretical modeling and experiments are implemented to reveal the fast response characteristics and adjustable mechanical characteristics of ECPA.Experimental results show that the deflation response speed of ECPA is increased by at least 3.1 times with the action of elastic components,what is more,the stiffness of ECPA is increased by 22 times.Based on the ECPA,two kinds of locomotion robots including a running robot(runs at an average locomotion speed of 6.3 BL/s(body lengths,BL))and an underwater swimming robot(achieves an average speed of 1.1 BL/s)are designed.The fast-moving robots both demonstrate high-speed mobility because of the rapid response and high strength of ECPA.展开更多
An innovative design of electric suspensions was developed in this study to help realize slow active suspension easily and quickly.This design was driven by screw through double slider-rod arranged symmetrically as a ...An innovative design of electric suspensions was developed in this study to help realize slow active suspension easily and quickly.This design was driven by screw through double slider-rod arranged symmetrically as a substitute for two springs.Based on a mathematical modeling,suspension parameters were introduced for a certain type of wheeled vehicles.The functions and its mechanism in regulating terrain clearance and adjusting attitudes were subsequently explained respectively,together with its semi-active control mechanism and characteristics In conclusion,our data in the study show that the new mechanical design of suspensions not only could realize adjusting terrain clearance and static vehicle pose,but also had an ideal stiffness that could realize a semi-active suspension function through adjusting suspension＇s stiffness.Therefore it can bequite suitable for off-road wheeled vehicles and military wheeled vehicles.展开更多
With the rapid development of space activities,non-cooperative space targets increase swiftly,such as failed satellites and upper stages,threating normal spacecrafts seriously.As there are some problems in the capture...With the rapid development of space activities,non-cooperative space targets increase swiftly,such as failed satellites and upper stages,threating normal spacecrafts seriously.As there are some problems in the capture process,such as excessive collision and fast tumbling of targets,manipulator with redundant Degrees of Freedom(DOFs)can be used to improve the compliance and therefore solve these problems.The Rope-Driven Snake Manipulator(RDSM)is a combina-tion of hyper-redundant DOFs and better compliance,and therefore it is suitable for capturing mis-sion.In this paper,a snake manipulator mechanism is designed,and the complete kinematic model and system dynamic model considering RDSM,target and contact is established.Then,to obtain the configuration of joint with hyper-redundant DOFs,an improved motion dexterity index is pro-posed as the joint motion optimization target.Besides,the force-position collaborative optimization index is designed to adjust active stiffness,and the impedance control method based on the modified index is used to capture the space target.Finally,the proposed force-position collaborative opti-mization method is verified by virtual prototype co-simulation.The results demonstrate that based on the proposed method,the collision force is reduced by about 25%compared to normal impe-dance control,showing higher safety.展开更多
Soft grippers due to their highly compliant material and self-adaptive structures attract more attention to safe and versatile grasping tasks compared to traditional rigid grippers.However,those flexible characteristi...Soft grippers due to their highly compliant material and self-adaptive structures attract more attention to safe and versatile grasping tasks compared to traditional rigid grippers.However,those flexible characteristics limit the strength and the manipulation capacity of soft grippers.In this paper,we introduce a hybrid-driven gripper design utilizing origami finger structures,to offer adjustable finger stiffness and variable grasping range.This gripper is actuated via pneumatic and cables,which allows the origami structure to be controlled precisely for contraction and extension,thus achieving different finger lengths and stiffness by adjusting the cable lengths and the input pressure.A kinematic model of the origami finger is further developed,enabling precise control of its bending angle for effective grasping of diverse objects and facilitating in-hand manipulation.Our proposed design method enriches the field of soft grippers,offering a simple yet effective approach to achieve safe,powerful,and highly adaptive grasping and in-hand manipulation capabilities.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.91748118 and 12032015)the Program of Shanghai Key Laboratory of Spacecraft Mechanism+2 种基金the National Natural Science Foundation for Distinguished Young Scholars of China(Grant No.11625208)the Program of Shanghai Academic/Technology Research Leader(Grant No.19XD1421600)the National Postdoctoral Program for Innovative Talents(Grant No.BX20190201)。
文摘The application of soft pneumatic actuators is typically hindered by the low strength and slow response speed caused by their intrinsic material limitation and unstressed stable form.In this work,we present a design strategy for improving the performance and response speed for Pneu-Nets actuators by incorporating adjustable elastic components to form the elastic composite pneumatic actuator(ECPA).The elastic energy storage of the elastic component is implemented to enhance the capability and speed up the response of ECPA and pre-bend the actuator.Due to the design principle,the fully-flexible ECPA is easy to manufacture and regulate.Theoretical modeling and experiments are implemented to reveal the fast response characteristics and adjustable mechanical characteristics of ECPA.Experimental results show that the deflation response speed of ECPA is increased by at least 3.1 times with the action of elastic components,what is more,the stiffness of ECPA is increased by 22 times.Based on the ECPA,two kinds of locomotion robots including a running robot(runs at an average locomotion speed of 6.3 BL/s(body lengths,BL))and an underwater swimming robot(achieves an average speed of 1.1 BL/s)are designed.The fast-moving robots both demonstrate high-speed mobility because of the rapid response and high strength of ECPA.
基金Supported by the Ministerial Level Research Foundation(4030.4)
文摘An innovative design of electric suspensions was developed in this study to help realize slow active suspension easily and quickly.This design was driven by screw through double slider-rod arranged symmetrically as a substitute for two springs.Based on a mathematical modeling,suspension parameters were introduced for a certain type of wheeled vehicles.The functions and its mechanism in regulating terrain clearance and adjusting attitudes were subsequently explained respectively,together with its semi-active control mechanism and characteristics In conclusion,our data in the study show that the new mechanical design of suspensions not only could realize adjusting terrain clearance and static vehicle pose,but also had an ideal stiffness that could realize a semi-active suspension function through adjusting suspension＇s stiffness.Therefore it can bequite suitable for off-road wheeled vehicles and military wheeled vehicles.
文摘With the rapid development of space activities,non-cooperative space targets increase swiftly,such as failed satellites and upper stages,threating normal spacecrafts seriously.As there are some problems in the capture process,such as excessive collision and fast tumbling of targets,manipulator with redundant Degrees of Freedom(DOFs)can be used to improve the compliance and therefore solve these problems.The Rope-Driven Snake Manipulator(RDSM)is a combina-tion of hyper-redundant DOFs and better compliance,and therefore it is suitable for capturing mis-sion.In this paper,a snake manipulator mechanism is designed,and the complete kinematic model and system dynamic model considering RDSM,target and contact is established.Then,to obtain the configuration of joint with hyper-redundant DOFs,an improved motion dexterity index is pro-posed as the joint motion optimization target.Besides,the force-position collaborative optimization index is designed to adjust active stiffness,and the impedance control method based on the modified index is used to capture the space target.Finally,the proposed force-position collaborative opti-mization method is verified by virtual prototype co-simulation.The results demonstrate that based on the proposed method,the collision force is reduced by about 25%compared to normal impe-dance control,showing higher safety.
基金supported by the National Key Research and Development Program of China under Grant 2022YFB4701204the Natural Science Foundation of China under Grants 52205031,52305013,and 52022056.
文摘Soft grippers due to their highly compliant material and self-adaptive structures attract more attention to safe and versatile grasping tasks compared to traditional rigid grippers.However,those flexible characteristics limit the strength and the manipulation capacity of soft grippers.In this paper,we introduce a hybrid-driven gripper design utilizing origami finger structures,to offer adjustable finger stiffness and variable grasping range.This gripper is actuated via pneumatic and cables,which allows the origami structure to be controlled precisely for contraction and extension,thus achieving different finger lengths and stiffness by adjusting the cable lengths and the input pressure.A kinematic model of the origami finger is further developed,enabling precise control of its bending angle for effective grasping of diverse objects and facilitating in-hand manipulation.Our proposed design method enriches the field of soft grippers,offering a simple yet effective approach to achieve safe,powerful,and highly adaptive grasping and in-hand manipulation capabilities.
