Design And Research Of Artificial Jellyfish Driven By Water Injection

Conventional underwater robots are mostly driven by propeller,which are inefficient in propulsion,poor in mobility,and easy to impact on the underwater environment,or even destroy the marine ecosystem.Those soft robots made of soft materials had the advantages of strong deformation ability and excellent flexibility.In this thesis,water-injection jellyfish robot based on soft materials is developed by combining soft actuators with jellyfish robot.The robot uses a small-sized DC submersible pump as the driving device,and the soft tentacle is used as the executive mechanism,which injects a certain pressure fluid into the soft tentacle to make it bend and deform,and achieve the swimming action of the jellyfish robot.The main research work in this thesis includes:(1)The mathematical model is established to analyze the propulsion force and the biological structure of jellyfish.The characteristics of jellyfish propulsion are summarized.The design requirement of this project is put forward.On this basis,the overall structure of water-injection jellyfish robot is designed and its swimming plan is explained.(2)By analyzing the force of jellyfish robot under water,the relationship between the speed of jellyfish robot and the bending variables of the soft tentacle is obtained,and the design requirements of the soft tentacle are put forward.By analyzing the mechanical properties of the soft materials and the flexural deformation of the tentacle,the concrete parameters of the soft tentacle are determined,then the material of soft tentacle was selected.The three-dimensional model of the soft tentacle is established and simulated,and the different hardness of the silicon rubber material and the parameters affecting the bending deformation are simulated.According to the simulation results,the main structure parameters of the soft tentacle are improved,and the structure of the soft tentacle is determined.(3)According to the structural parameters of the soft tentacle,the mold is made by 3D printing.Silicone rubber is poured to form the soft tentacle.The jellyfish robot produced by 3D printing technology is the main structure,and each part is assembled to complete the jellyfish robot prototype.In order to detect the flexural deformation characteristics of the soft tentacle,a test platform is set up.By comparing the experimental results and simulation curves,it is found that the soft tentacle can achieve large continuous amplitude bending deformation under the pressure of 50kPa,and the trend of bending matches the simulation results.The test platform is set up to test the response time of the soft tentacle.The results show that the performance of the soft tentacle can meet the technical requirements proposed.(4)The control system of the jellyfish robot is designed,and the circuit board is designed and completed.The PCB board is inserted into the jellyfish robot prototype for debugging.The jellyfish prototype can perform periodic swaying.According to the test results of the linear swimming characteristics of jellyfish prototype,the results show that the a jellyfish prototype has good swimming characteristics and the maximum speed is 24mm/s.The test also proves that the water-injection jellyfish robot design proposed is reasonable and feasible.