Soft pneumatic robotic grippers have found extensive applica-tions across various engineering domains,which prompts active research due to their splendid compliance,high flex-ibility,and safe human-robot interaction o...Soft pneumatic robotic grippers have found extensive applica-tions across various engineering domains,which prompts active research due to their splendid compliance,high flex-ibility,and safe human-robot interaction over conventional stiff counterparts.Previously simplified rod-based models prin-cipally focused on clarifying overall large deformation and bending postures of soft grippers from static or quasi-static perspectives,whereas it is challenging to elaborate grasping characteristics of soft grippers without considering contact interaction and nonlinear large deformation behaviors.To address this,based on absolute nodal coordinate formulation(ANCF),comprehensively allowing for structural complexity,geometric,material and boundary nonlinearities,and incorpor-ating Coulomb’friction law with a multiple-point contact method,we put forward an effective nonlinear dynamic mod-eling approach for exploring grasping capability of soft grip-per.Moreover,we solved the established dynamic equations using Generalized-αscheme,and conducted thorough numer-ical simulation analysis on a three-jaw soft pneumatic gripper(SPG)in terms of grasping configurations,displacements and contact forces.The proposed dynamic approach can accurately both describe complicated deformed configurations along with stress distribution and provide a feasible solution to simulate grasping targets,whose effectiveness and precision were analyzed theoretically and verified experimentally,which may shed new light on devising and optimizing other multi-functional SPGs.展开更多
Pneumatic soft robots have undergone significant advancements in recent years.However,the majority of robot motion control still relies on electronic computers to regulate the valves and air pumps.Despite the potentia...Pneumatic soft robots have undergone significant advancements in recent years.However,the majority of robot motion control still relies on electronic computers to regulate the valves and air pumps.Despite the potential reduction in controller dependency by utilizing soft pneumatic oscillators,challenges such as low flow rates,complex manufacturing processes,and lack of adjustment ability persist.Inspired by the geckos'spine,we propose a Spinal Bistable Oscillator(SBO)that operates without discrete components or electronic control hardware,achieving stable oscillatory motion under constant air pressure.This oscillator employs a soft control valve and lagging pin,which can switch the direction of airflow conduction based on the oscillation angle of the spine.Different types of actuators can be controlled using a series connection.In this study,the effective working range of the soft control valve,influence of the spring pretension force on the torque during oscillation,and effect of different throttle tube lengths on the oscillation frequency were investigated.Furthermore,a self-crawling robot was developed.Experimental results demonstrate that the robot can crawl at speeds ranging from 3.6 to 5.7 mm/s(or 3.1 to 4.9 body length/min)and overcome its own gravity(with a weight of 165 g)to climb vertically.The SBO proposed in this study exhibits characteristics of lightweight,low cost,high oscillation torque,and tunable frequency.It holds promise for application in joint control of future pneumatic soft robots.展开更多
Bio-inspired soft robots have already shown the ability to handle uncertainty and adapt to unstructured environments.However,their availability is partially restricted by time-consuming,costly,and highly supervised de...Bio-inspired soft robots have already shown the ability to handle uncertainty and adapt to unstructured environments.However,their availability is partially restricted by time-consuming,costly,and highly supervised design-fabrication processes,often based on resource-intensive iterative workflows.Here,we propose an integrated approach targeting the design and fabrication of pneumatic soft actuators in a single casting step.Molds and sacrificial water-soluble hollow cores are printed using fused filament fabrication.A heated water circuit accelerates the dissolution of the core’s material and guarantees its complete removal from the actuator walls,while the actuator’s mechanical operability is defined through finite element analysis.This enables the fabrication of actuators with non-uniform cross-sections under minimal supervision,thereby reducing the number of iterations necessary during the design and fabrication processes.Three actuators capable of bending and linear motion were designed,fabricated,integrated,and demonstrated as 3 different bio-inspired soft robots,an earthworm-inspired robot,a 4-legged robot,and a robotic gripper.We demonstrate the availability,versatility,and effectiveness of the proposed methods,contributing to accelerating the design and fabrication of soft robots.This study represents a step toward increasing the accessibility of soft robots to people at a lower cost.展开更多
基金supported by Natural Science Foundation of Zhejiang Province (Grant No.LQ22A020003)National Natural Science Foundation of China (Grant No.52075499)for which all authors are grateful.
文摘Soft pneumatic robotic grippers have found extensive applica-tions across various engineering domains,which prompts active research due to their splendid compliance,high flex-ibility,and safe human-robot interaction over conventional stiff counterparts.Previously simplified rod-based models prin-cipally focused on clarifying overall large deformation and bending postures of soft grippers from static or quasi-static perspectives,whereas it is challenging to elaborate grasping characteristics of soft grippers without considering contact interaction and nonlinear large deformation behaviors.To address this,based on absolute nodal coordinate formulation(ANCF),comprehensively allowing for structural complexity,geometric,material and boundary nonlinearities,and incorpor-ating Coulomb’friction law with a multiple-point contact method,we put forward an effective nonlinear dynamic mod-eling approach for exploring grasping capability of soft grip-per.Moreover,we solved the established dynamic equations using Generalized-αscheme,and conducted thorough numer-ical simulation analysis on a three-jaw soft pneumatic gripper(SPG)in terms of grasping configurations,displacements and contact forces.The proposed dynamic approach can accurately both describe complicated deformed configurations along with stress distribution and provide a feasible solution to simulate grasping targets,whose effectiveness and precision were analyzed theoretically and verified experimentally,which may shed new light on devising and optimizing other multi-functional SPGs.
基金supported by Sichuan Provincial Department of Science and Technology Key Research and Development Program in High-Tech Fields(2022YFG0240).
文摘Pneumatic soft robots have undergone significant advancements in recent years.However,the majority of robot motion control still relies on electronic computers to regulate the valves and air pumps.Despite the potential reduction in controller dependency by utilizing soft pneumatic oscillators,challenges such as low flow rates,complex manufacturing processes,and lack of adjustment ability persist.Inspired by the geckos'spine,we propose a Spinal Bistable Oscillator(SBO)that operates without discrete components or electronic control hardware,achieving stable oscillatory motion under constant air pressure.This oscillator employs a soft control valve and lagging pin,which can switch the direction of airflow conduction based on the oscillation angle of the spine.Different types of actuators can be controlled using a series connection.In this study,the effective working range of the soft control valve,influence of the spring pretension force on the torque during oscillation,and effect of different throttle tube lengths on the oscillation frequency were investigated.Furthermore,a self-crawling robot was developed.Experimental results demonstrate that the robot can crawl at speeds ranging from 3.6 to 5.7 mm/s(or 3.1 to 4.9 body length/min)and overcome its own gravity(with a weight of 165 g)to climb vertically.The SBO proposed in this study exhibits characteristics of lightweight,low cost,high oscillation torque,and tunable frequency.It holds promise for application in joint control of future pneumatic soft robots.
基金supported by Portuguese national funds through FCT-Fundacao para a Ciencia e a Tecnologia,[grant numbers UIDB/00285/2020,LA/P/0112/2020,and 2022.13512.BD].
文摘Bio-inspired soft robots have already shown the ability to handle uncertainty and adapt to unstructured environments.However,their availability is partially restricted by time-consuming,costly,and highly supervised design-fabrication processes,often based on resource-intensive iterative workflows.Here,we propose an integrated approach targeting the design and fabrication of pneumatic soft actuators in a single casting step.Molds and sacrificial water-soluble hollow cores are printed using fused filament fabrication.A heated water circuit accelerates the dissolution of the core’s material and guarantees its complete removal from the actuator walls,while the actuator’s mechanical operability is defined through finite element analysis.This enables the fabrication of actuators with non-uniform cross-sections under minimal supervision,thereby reducing the number of iterations necessary during the design and fabrication processes.Three actuators capable of bending and linear motion were designed,fabricated,integrated,and demonstrated as 3 different bio-inspired soft robots,an earthworm-inspired robot,a 4-legged robot,and a robotic gripper.We demonstrate the availability,versatility,and effectiveness of the proposed methods,contributing to accelerating the design and fabrication of soft robots.This study represents a step toward increasing the accessibility of soft robots to people at a lower cost.
