Study On Attitude Maneuver Nonlinear Dynamic Modeling And Component Synthesis Vibration Suppression

In recent years, the applications of flexible accessories are quite widely with therapid development of space science, such as solar arrays, flexible manipulator. Theapplication of the flexible structure damaged the stiffness of the spacecraft, making theoriginal dynamic modeling based on rigid body not applicable. Accompanied with theflexibility, the equation of the Spacecraft is nonlinear. In addition, the accuracy controlof the Spacecraft attitude is becoming difficult as flexible accessories in space are veryeasy to vibrate and can not decay in a short time. In the opposite, the requirement of theaccuracy on space missions is becoming strictly. Therefore, the nonlinear dynamicmodeling and the vibration suppression are very important.This thesis make a study from the following three aspects based on the twoquestions.Firstly, establishing a dynamic modeling of the flexible satellite. The specificprocess is: Using the finite element method to characterize the elastic deformation offlexible bodies to be the forms of nodal displacement matrix; Using the basic equationof vector mechanics characterize the motion of the center rigid body; Using theLagrangian equation establish the attitude maneuver equation and vibration equation ofthe system. The simulation analysis is hard to carry because the the the number of theequation dimensions established by the finite element method is too large. So we haveto reduce the dimensions.Secondly, Indicating some basic principles of CSVS, and clarifying the mothed ofvibration suppression of multi-vibration mode and the robustness of the CSVS.Finally, Using CSVS in the maneuver of the flexible satellites. Simplifying themodeling into the linear equation, verificating the CSVS. Considering that the CSVScontroller can suppress the vibration, the vibration can be ignored, then the nonlinearequation can be simplified to be the linear equation. Based on the above consideriton,the CSVS controller designed in linear situation can be used in the nonlinear situation,observing the result of the CSVS. Lastly, Using the robustness of the CSVS suppress theresidual vibration caused by the imprecise frequency.