Design And Experimental Research On Bionic Manta Ray Driven By SMA

Bionic robot fish combines bionics and robotics,has great research prospects and application value,and can provide great help for human beings.There are two kinds of propulsion methods of bionic robot fish: caudal fin propulsion and pectoral fin propulsion.The former has fast swimming speed,while the latter has smooth movement.These two methods have their own advantages and disadvantages,which can be selected according to the performance requirements.At present,the driving problem of bionic robot fish is mostly driven by motor,but the two biggest disadvantages of this way are noise and not flexible enough,so more and more scholars begin to use intelligent driving materials reasonably.This paper used SMA,which is the most suitable driving material with large output force and small voltage and short reaction time.In this paper,the author first took manta ray as the bionic object,and designed a kind of bionic manta ray driven by SMA wire according to its special shape and motion mechanism.The shape structure and internal driving structure were designed.Then,the driving characteristics of the bionic pectoral fin were theoretically modeled,and the curves of the temperature of SMA wire and the swing angle of the bionic pectoral fin with respect to the current were obtained,which provided a theoretical basis for the following control and experimental parts.In order to understand the propulsive way of pectoral fin more intuitively,this paper carried on the simulation analysis for the bionic pectoral fin,used the FLUENT software to carry on the three-dimensional swing simulation,used the dynamic grid technology,combined with the UDF program,obtained the pressure diagram of the pectoral fin swing process and the thrust and lift curves.The influence of swing amplitude,swing frequency,flow velocity and other parameters on hydrodynamics was analyzed and compared,and the propulsion performance of pectoral fin was more deeply understood.Finally,the control system was designed based on the theory and simulation analysis.The physical prototype was made,and the experimental test was carried out.Firstly,the swing angle test,compared with the theoretical analysis,verified the correctness.And then the author carried out the swimming test,analyzed the causes of the error,and obtained the maximum speed of the prototype is 27.3mm/s,the maximum turning angular speed is 12.5 °/ s and the minimum turning radius is 0.26 m.