Adjustable stiffness elastic composite soft actuator for fast-moving robots

摘要

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.