Topological Bionic Lightweight Design Of The Leg Structure Of A Hydraulic Quadruped Robot

With the development of science and technology,hydraulic quadruped robots are replacing humans in more and more occasions.The leg structure is the load-bearing structure of the hydraulic quadruped robot,and its mass directly affects the motion response speed and endurance of the robot.At present,the lightweight design of the leg structure often adopts the bionic idea to design the joint structure of the leg,or adds weight-reducing holes or weight-reducing grooves on the basis of the traditional structure.The lightweight effect is limited and the fatigue life of the structure is not considered.This study aims to reduce the leg mass of the hydraulic quadruped robot,the lightweight design of the main structure of the leg—yaw,calf and thigh structure is carried out.The main research contents are as follows:(1)The dangerous working conditions of the leg structure are determined by analyzing the dynamic simulation results,which lays the foundation for the subsequent lightweight design of the structure.The finite element simulation model of leg structure assembly under dangerous working conditions is established.The finite element simulation results are analyzed to determine the lightweight objects as the main components of leg structure--yaw structure,leg structure and thigh structure.(2)With the help of the structural bionic design idea,the wheat stalk was determined as the bionic prototype and the similarity was evaluated.A multi-objective dimensional optimization strategy of bionic yaw with fatigue life as the constraint and mass and deformation as the optimization objective is given.The bionic yaw model is obtained and its performance is verified,which is the basis for the subsequent establishment of the lattice structure.(3)Establish a variable-density topology optimization model of the calf structure and thigh structure,establish a simulation model of the optimized structure,and give a parameter optimization strategy based on a multi-objective genetic algorithm.Lay the foundation for further lightweighting.(4)In order to further reduce the weight of the leg structure,a topological optimization model of bionic yaw,topological calf and topological thigh with stiffness as the optimization goal is established.A variable density lattice structure model is established based on the cell density.Finite element analysis is carried out on the optimized leg model,and the optimization effect is verified with reference to the fatigue life,stiffness and strength of the original structure.