Design And Verification Of Satellite Antenna Pointing Mechanism

Two-dimensional satellite antenna pointing mechanism is an executive component used in satellite system to realize the functions of pointing to,positioning of and tracking ground targets.When the satellite platform is on orbit,the joint movement in two directions of the pointing mechanism enables the satellite communication antenna to always maintain the precise pointing to the ground station,thus completing the information transformation between the satellite system and the ground station.Meanwhile,there will be mutual interference between the pointing mechanism and the satellite platform in the course of motion.On the one hand,the movement of the pointing mechanism will interfere the attitude of satellite,and even overturn the satellite.On the other hand,the attitude disturbance of satellite will also cause the deviation of antenna pointing.The purpose of this paper is to design two new kinds of satellite pointing mechanisms for communication antenna of satellites: Large parabolic antenna pointing mechanism and small horn antenna pointing mechanism,and optimization and improvement of the design will be done to ensure the economical efficiency,rationality and reliability of the mechanism design through mechanical simulation analysis.Thirdly,it can analyse the influence of pointing mechanism movement on satellite attitude based on satellite attitude dynamics equation and ADAMS simulation software.Finally,it completes the development of the physical object and the ground verification test.This paper mainly studies the following 4 aspects:(1)According to the design requirements and taking full account of the limitations of the space environment,we have proposed the mechanical structure design schemes of the two kinds of pointing mechanism including drive unit,deceleration unit,angle detection unit and support unit,and used three-dimensional software to finish the geometric model of pointing mechanism.(2)This paper established the finite element model of the mechanism by HyperMesh software,and completed the mechanical simulation analysis of the pointing mechanism,including static analysis,modal analysis,harmonic response analysis and random vibration analysis.Through simulation results,it veified the mechanism satisfy the design requirements.It improved and optimized the structure based on the simulation results and determined the final design plan.(3)Based on the attitude dynamics equation of the satellite system,it completed the dynamic coupling analysis of the satellite system and analyzed the influence of pointing mechanism motion on the attitude angle of the satellite by ADAMS software simulation.(4)Baded on previous studies,we completed the development of small pointing mechanism entity,designed the ground verification test,assembled the mechanism,builded the experimental platform,simulated space environment and completed the mechanical test,life test and cold welding test of pointing mechanism in order to verify that the mechanism can withstand the harsh space environment and satisfy the life design requirements.