Research On Dynamic Modeling And Vibration Control Of Large Space Truss Structure On-orbit Construction

The continuous development of space technology has made the large-scale space truss structures widely used,but the large-scale space truss structure faces the problem of being built in orbit,and has the characteristics of complex and large flexibility,so dynamic modeling and vibration control become the focus of its research.In this paper,the large-scale truss structure which shaper is looks like ‘jing' is taken as the analysis object,and the system's on-orbit construction scheme,dynamics modeling,dynamic analysis,attitude control and vibration suppression are studied.The main research contents are as follows:Establish the dynamic model of truss structure in the process of on-orbit construction and based on the central rigid body-flexible attachment model,the dynamic model of large space truss structure is established and the modal frequency and flexible coupling coefficient of the solar wing are calculated by finite element method,which lays a foundation for the subsequent attitude control.Aiming at the problem of on-orbit construction of large-scale space truss structure,Using the large-scale space truss structure which is similar to the "jing" type as an example,a construction scheme is designed.The construction scheme is analyzed from the two aspects of gravity gradient moment and moment of inertia,which is proved to have good stability.The finite element method is used to model the large space truss structure.We do the modal analysis,harmonic response analysis and transient analysis of the large space truss structure which is used the ANSYS Workbench software.The analysis results show that the large space truss structure has the characteristics of low frequency and dense frequency.When the structure is applied a force,it will cause vibrations and the vibrations are difficult to decay rapidly.Aiming at the attitude deviation of large space truss structure during orbit construction,an attitude control system which use gravity gradient torque and thruster as actuator is designed.The simulation results show that the designed control scheme can maintain the attitude of large space truss structure in the small angle range.And using the gravity gradient torque to control attitude can save fuel of the thrust control.Aiming at the vibration suppression problem caused by the truss structure in the attitude maneuvering process,two control schemes of PD combined input shaper and PD combined input shaper with positive position feedback(PPF)were designed.The simulation results which is based on the co-simulation with ANSYS,ADAMS and Simulink show that compared with the single PD control scheme,the two control schemes can effectively suppress the structural vibration generated by the truss structure during the attitude maneuvering process.The input shaper and PPF are two effective active vibration control methods.