Research On The Influence Of Key Dimension Tolerance Of Complex Space Rod System On Assembly Accuracy

Synthetic Aperture Radar(SAR)technology has become an important means of obtaining information from Earth observation.Spaceborne SAR can observe the earth all-weather and all-weather without being restricted by weather conditions.Therefore,it has unique advantages in disaster monitoring,environmental monitoring,ocean observation,resource prospecting,crop yield estimation,forest investigation,surveying and mapping,etc.These advantages make the demand for radar satellite applications continue to increase.SAR antenna deployment mechanism is a key subsystem of spaceborne SAR.Before and after the satellite enters orbit,the SAR antenna needs to complete the corresponding folding and unfolding actions.Its mechanism flatness,connection stability,and unfolding reliability directly affect the observation accuracy and performance of the satellite,and are the key factors related to the success or failure of the entire satellite.This subject takes the SAR antenna deployment mechanism as the analysis object,and studies the influence of the complex rod system on the assembly accuracy,and completes the analysis of the influence of the assembly stress on the assembly accuracy and mechanism tolerance and the planning of the assembly sequence.The development and assembly links provide the relevant theoretical basis.The main research contents and results of the paper are as follows:(1)According to the characteristics of the large size of the deployment mechanism,many parts,complex rod system and mutual coupling,the finite element software is used to establish the model of the deployment mechanism,and the assembly stress between the rods is simulated by setting the prestressed boundary conditions.The influence of the assembly stress of the antenna rod system in the deployment mechanism on the assembly accuracy of the antenna panel is studied,and the mapping relationship between the size of the antenna rod system and the flatness of the antenna panel is determined.(2)Through theoretical tolerance analysis of the deployment mechanism,an analysis model is established,the assembly dimension chain is defined,and the tolerance analysis software Vis VSA is used to analyze the assembly deviation of the deployment mechanism,and then the assembly sensitivity and contribution data of the antenna rod system are obtained..Since the simulation results do not meet the requirements of assembly accuracy,the scheme is further optimized,and the optimal assembly tolerance is obtained,thereby determining the components with the most assembly sensitivity.(3)Based on the above research,the key components are determined,and the assembly datum is optimized and the assembly priority is quantified by considering the influencing factors such as the geometric structure of the part,the accuracy measurement datum,and the coupling effect of the assembly stress,so as to finally ensure the complex rod system.The connection and fit meet the requirements of better assembly accuracy.