Design Of Flexible Gripper Based On Dielectric Elastomer

Traditional rigid robot has been widely used in industrial production and life because of its unique advantages such as high efficiency,high output efficiency and good control accuracy.With the development of intelligent soft materials,the special robot form of soft robot emerges.Intelligent soft materials can be controlled in more diversified ways because of their soft body and external stimulation response,and realize continuous large deformation and automatic adaptation to complex scenes.This paper starts from the intelligent soft material of soft robot,through studying the material characteristics of acrylic dielectric elastomer,establishing the balance equation under the state of force and electricity coupling,measuring the parameters of material super elastic model,studying the reason of deformation of the dielectric elastomer driver based on the minimum energy structure,and combining with the static characteristics of the driver,the optimization principle is proposed,On this basis,the flexible grip is developed and tested.Based on the theory of thermodynamics and continuum mechanics,the deformation principle of dielectric elastomer materials under the cooperation of force and electricity coupling is analyzed.The state equation of dielectric elastomer materials is deduced by nominal and real physical quantity.The super elastic model and viscoelastic model of dielectric elastomer are studied.The parameters and dielectric constant values of the material are obtained by experimental tests.The viscoelastic and super elastic properties of dielectric elastomer materials cause the complex internal stress condition when analyzing the static properties of the actuator,so the constitutive relationship of the actuator cannot be effectively constructed.The reason why the dielectric elastic film on the bending region will produce a special bulge shape when the actuator is bent in three-dimensional state is analyzed.Based on the coupling model of the electro-mechanical deformation force of dielectric elastomer and the basic mechanical properties of the materials,the paper analyzes the Yeoh super elastic strain energy model based on Gaussian distribution.The relationship between the shape of hollow area,thickness of pet frame,pre drawing ratio of film and the static equilibrium angle of dielectric elastomer was summarized by comparing experiment and simulation.According to the deformation of the dielectric actuator in the static equilibrium state and the deformation state after the power on,the specific evaluation parameters of the dielectric elastomer driver are proposed,which are the static balance angle,the power on change angle and the film torque to pet frame.The static equilibrium angle and the moment of film to pet frame are taken as two main evaluation parameters of optimization principle.According to the stress relationship between dielectric elastomer film and pet frame,the relationship between the moment of dielectric elastomer film and the size of the empty area can be deduced through formula.It is established under different static balance angle,hollow area shape,pet frame thickness and shape.The relationship is verified by measuring the force at the tip of the driver.The optimization principle of dielectric elastomer driver is also proposed.The basic driving unit of the flexible grab is designed by the above theoretical method,and the two-finger flexible grab is designed and manufactured by using the new structure as the basic unit.Finally,it is successfully applied to the load grab and handling task,and the ultra-light and continuous large deformation behavior of the flexible grab is realized.