| With the gradual acceleration of human demand for ocean exploration and exploitation,the research and development of underwater robots have received extensive attention from scholars at home and abroad.Some researchers have integrated bionic theory into the research process of underwater robots and developed many bionic underwater robots based on biological prototypes,which have the characteristics of light weight,high efficiency,no pollution,low noise and high flexibility compared with traditional underwater robots.At present,the prototypes of bionic underwater robots are mostly designed for fish,and the related researches are more mature and are practically applied in marine environment monitoring and survey work.Based on the diversity of marine organism populations and the differences in movement and motivation,jellyfish have become the focus of research in the field of bionics with their unique swimming patterns.In recent years,some researchers have used jellyfish as bionic prototypes to develop underwater robots,but the starting time is relatively short and there are limitations in related research.In this paper,we combine the advantages of bionic theory and soft body drive to design a bionic jellyfish robot based on hydraulic drive.In this paper,we take the red moon jellyfish as the research object,measure its body size and analyze its motion morphology changes,and establish the bionic jellyfish robot dynamics model by combining the jellyfish dynamics formula.Comparing the structure and driving methods of soft body drive,the hydraulic soft body drive is selected to actively drive the bionic jellyfish robot.It has good flexibility and reliability.By studying different fabrication processes,material models and simulation methods,it is determined to use casting molding fabrication process,Yeoh material model and finite element analysis simulation method to study the bionic jellyfish robot.Design the bionic jellyfish structure,its drive method and the function of each part of the parts with the idea of circular design.Design the ideal soft body drive,including the central soft body drive and the drive arm soft body drive,and simulate its performance using the finite element software ABAQUS.Use Matlab & Simulink to simulate the dynamics of the bionic jellyfish,optimize the parameters of the initial angle of the bionic jellyfish drive arm,swing angle,and length of the rigid drive arm,and propose an optimization scheme for the control of the soft body drive.The CFD software Fluent is used to simulate and analyze the flow field distribution under different swimming conditions of the bionic jellyfish,and verify the rationality and reliability of the design by analyzing the vector diagram and cloud diagram of the flow field pressure and velocity.Select the pump used by the bionic jellyfish according to the volume change of the soft body drive and the control optimization scheme.Complete the fabrication of the soft body drive and each part of the bionic jellyfish,in which the soft body drive is made by casting molding and each part is made by 3D printing technology.Calculate the center of gravity and floating center of the bionic jellyfish according to the weight and shape of the fabricated parts,so that it can meet the swimming requirements.The completed prototype of the bionic jellyfish is demonstrated,the instruments required for the bionic jellyfish test experiment are explained,and the requirements to be met by the bionic jellyfish control system and the system component hardware are briefly explained.Afterwards,the jellyfish is debugged and its performance is tested,the composition and test contents of the experimental system are explained,and the experimental results are collected and counted.Finally,the data obtained are analyzed and conclusions are drawn.The experiments show the feasibility of the bionic jellyfish control method and structure design.The combination of hydraulic flexible actuators and bionic jellyfish exhibits a high degree of adaptability. |
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