Research On BCF Bionic Robot Fish Driven By Dielectric Elastomer

Bionic robot fish have been widely used in various underwater exploration activities due to their advantages of low noise,low resistance,high flexibility and high concealment.At present,the common actuation methods of bionic robot fish mainly include motor actuation,gas/fluid actuation,shape memory alloy actuation and ionic polymer-metal composite actuation.They also have the defects of complex structure,huge driving source and poor environmental adaptability,which limit the motion scene and range of the bionic robot fish.Dielectric elastomer is a soft material that can produce significant deformation under the action of an electric field.In this article,the main research and achievements are as follows:(1)The antagonistic structure is analyzed mechanically and designed,which can be realized under the action of alternating driving voltage.A limit piece is introduced inside the actuator to improve the distortion after the actuator is actuated.(2)The displacement test platform and the output force test platform are built to conduct a series of tests on the antagonistic dielectric elastomer actuator.The relationship between the end displacement,actuation voltage and actuation frequency of the actuator are obtained,and the relationship between the output force,actuation voltage and actuation frequency of the actuator are obtained.The results show that the greater the actuation voltage,the greater the end displacement and output force,the maximum end displacement is 6.48mm,and the maximum output force is 48.54mN.The underwater actuation method of the actuator and the actuation circuit are proposed;the passive tail fin is introduced into the actuator to improve the swing performance of the actuator,and an underwater test platform is built to test the underwater swing performance of the actuator after introducing the passive tail fin.(3)The flexible swing of the passive tail fin in the flow field is simulated by the dynamic grid technology in the FLUENT software.The propulsion force of the passive tail fin swinging in the flow field is obtained through CFD numerical calculation.The average propulsion force of the passive tail fin under different parameters is calculated,and the maximum propulsion force is 14.29mN.(4)The structure of the bionic robot fish is designed,and the antagonistic dielectric elastomer actuator is used as its driving source.A BCF bionic robot fish prototype is proposed.An underwater test platform is built to conduct underwater downstream dynamic experiments to test its underwater propulsion performance and verify the feasibility of the antagonistic dielectric elastomer actuator as the driving source of the bionic robot fish.The fastest swimming speed of the bionic robot fish can reach 22.7mm/s,which is about 1/7 body length.