Lightweight Design Of Miniaturized Hydraulic Power Unit Based On Sobol Sensitivity Analysis

Taking hydraulic legged robot as an example,most hydraulic mobile equipment has the requirements of high control accuracy,large load capacity and long endurance.Reducing its own weight can effectively improve the above problems.How to reduce its own weight has been a hot issue in the research of hydraulic legged robot.The lightweight design method based on hydraulic power unit is one of the effective methods to reduce dead weight and improve the power to weight ratio.This thesis studies the lightweight design of hydraulic power unit miniaturized by hydraulic legged robot,and the main research work is as follows:(1)Based on the working environment and control characteristics of hydraulic legged robot,the principle design of miniaturized hydraulic power unit is completed.Based on the moving gait of hydraulic legged robot,the basic parameters of hydraulic power unit are determined and the matching of hydraulic components is completed.The mathematical model of each component is analyzed and the whole simulation model of hydraulic power unit is established in MATLAB/Simulink.The principle of hydraulic power unit is verified by simulation analysis.(2)In order to determine the key parameters affecting the quality of hydraulic power unit,a multi-parameter,high-coupling and nonlinear hydraulic power unit quality model is established based on the structural characteristics and installation relationship of each component of hydraulic power unit.The hydraulic power unit quality model was verified based on sample data and physical modeling.Based on the global sensitivity analysis method of Sobol,the global sensitivity analysis of hydraulic power unit quality model parameters is carried out,and the key factors affecting the quality of hydraulic power unit are obtained.(3)Based on the influencing factors of hydraulic power unit quality,the lightweight design and research objectives of hydraulic power unit are determined,including low pressure tank,filter,motor pump and integrated block.Based on the structural characteristics,installation constraints,matching parameters and design criteria,the multiparameter extreme value analysis of the low pressure tank and filter is carried out.According to the matching relationship between motor and pump,pump and pressure,pump quantity and flow,the selection model of motor pump group with parameters and quality optimization was established.Based on the circular arc search algorithm and the maze algorithm,the component layout and the oil path of the block were optimized to complete the integrated design of the block.The lightweight hydraulic power unit model is established and analyzed in Solid Works.(4)In order to verify the lightweight design results of the hydraulic power unit,the lightweight hydraulic power unit is weighed and assembled.In order to test the structural performance and output characteristics of the hydraulic power unit after lightweight,the hydraulic power unit is sealed,maintained pressure and tested for trial operation,and the hydraulic test bench is built.And the light weight hydraulic power unit based on speed control of variable flow,variable load,variable motor pump number of output characteristics of the experiment and analysis.