| Sea turtles,penguins and other marine creatures have a unique body structure and movement mode,which is called flapping wing movement.It has the advantages of high energy utilization rate,high flexibility,low noise and strong stability at low speed.Further study of this unique motion mode and application of flapping wing motion mode to the design of underwater vehicle will play an important role in improving the performance of underwater vehicle.Compared with the traditional motor drive mode,soft materials have many advantages,such as light weight and high energy density,and the deformation mechanism of soft materials is similar to biological muscles.Flexible joints made of soft materials can better simulate biological muscle movements.The application of soft materials in bionic drive will greatly enhance the performance of micro and small robots.In this paper,numerical simulation,theoretical calculation and experiment are used to study the deformation mechanism of flexible joints of dielectric elastomer,the propulsion mechanism and propulsion capacity of flapping wing,and the hydrodynamic characteristics of streamlined shell.The main research contents include the following aspects:Study on flexible joint characteristics and hydrodynamic performance of flapping wing.Firstly,based on the deformation principle of dielectric elastomer,the denaturation ability of flexible joint was analyzed theoretically,and the deformation angle of joint was optimized by numerical simulation.Then,the propulsion mechanism of flapping wing motion is described,and the flapping wing chord section model is established in a two-dimensional plane.The numerical simulation of flapping wing motion with three different degrees of freedom is carried out by using computational fluid dynamics method,and the simulation results are analyzed.Finally,the influence of structural parameters and motion parameters on the propulsive performance of the two-degree-of-freedom flapping wing is studied.Shell design optimization and hydrodynamic characteristics study.Firstly,combined with the existing form of underwater vehicle shell,the combination of streamline and frame shape is selected.Secondly,the shape characteristics and structural parameters of various streamlined curves are described.The hydrodynamic characteristics of the three-dimensional model are simulated numerically,and the optimal hydrodynamic characteristics are selected as the shell curve of the soft underwater robot.Finally,the stability of the underwater soft robot is enhanced by applying a tail fin to the tail of the shell,and the tail fin is optimized by hydrodynamic simulation.Research on dynamic modeling and propulsion capability of soft underwater robot.Based on the analysis of the overall force of the underwater soft robot,a dynamic model of the underwater soft robot is established based on Newton-Euler equation.The motion simulation system of the underwater soft robot was established based on Matlab-Simulink platform,and the influence of the number of flapping wing thrusters and the frequency of flapping wing movement on the motion performance was studied.Experimental platform construction and experimental results analysis.An experimental platform was built to test and verify the motion ability of the soft underwater robot.By comparing the experimental results with the simulation results,the correctness of the simulation results is verified. |
