Hydrodynamic Optimization Design And Propulsion Characteristics Of Bionic Robot Crab

As a new type of underwater robot,underwater glider has the advantages of low energy consumption,strong battery life and low cost.As a mature underwater crawling robot,the bionic crab has the characteristics of high flexibility and multiple functions,but the crawling speed is slow,and it is not easy to switch the site,which has limitations.The main purpose of this article is to explore the development of a type of amphibious robot that has the characteristics of flexibility and stability of the bionic crab,low energy consumption of the underwater glider,and long operating time.Analysis and optimization of its initial shape based on lift-to-drag ratio.Finally,the self-propelled performance of the bionic robot crab coupled with the propeller was studied.The main research contents are as follows:(1)The overall design of the bionic robot crab.Using a modular method to design the bionic machine crab system,based on the statics and maneuverability of the aircraft,the overall planning of the bionic machine crab,preliminary calculation of the total weight,buoyancy,center of gravity,buoyancy of the bionic machine crab to complete the bionic machine crab The stability calculation of the pressure tank module adopts the crab body design,and uses the finite element method to check the structural strength of the pressure tank,and the initial hydrodynamic shape is introduced into the fusion layout of the aviation wing.The buoyancy adjustment system and the attitude adjustment system were selected through the comparison of schemes.On this basis,the selection of the internal system of the bionic machine crab was completed,which provided guidance for the construction and debugging of the bionic machine crab control system and the manufacture and assembly of the prototype.(2)Taking into account the hydrodynamic characteristics of the complex bionic robot crab.Based on the CFD software,the mechanical analysis of the steady glide state of the bionic robot crab under water is carried out,a numerical calculation model is established,the hydrodynamic performance prediction is performed on the initial shape,the lift-up resistance characteristics at different speeds and different angles of attack are obtained,and the pressure The field,velocity field and vorticity field are analyzed.Obtained the optimal angle of attack for the bionic robot crab to float and dive in the gliding state,and laid the foundation for the parametric modeling and the hydrodynamic shape optimization design of the bionic robot crab.(3)The shape optimization design of the bionic machine crab.First of all,according to the characteristics of the bionic robot crab's shape,its plane shape and span thickness distribution were separately designed,and the parametric design was carried out by the parametric method of tracing.Based on the CAESES software to write feature definitions,complete the automatic generation of bionic machine crab three-dimensional model.With the goal of improving its lift-to-drag ratio,the shape optimization design research was carried out.Based on the genetic algorithm,the bionic robot crab was optimized at the design speed and the wing configuration line.The optimized bionic robot crab has better hydrodynamic performance.(4)Research on the self-propelled performance of the bionic robot crab coupled with the propeller.Firstly,the open water performance of the ducted propeller is solved,and then the numerical prediction model of self-propelled performance of the bionic machine crab body-multi-paddle coupling system in self-propelled mode is established,and the self-propelled kinematic performance value of the propeller at different speeds in the direct mode is completed.Calculate and conduct research on the self-propelled performance of the bionic robot crab.