Micro-vibration Disturbance Response Analysis Of High-resolution Satellite

With the more and more urgent demands for high-resolution remote sensingsatellite to our country, related technological problems which constrain the resolution ofremote sensing satellite, need to be broken through. For higher requirement for line ofsight stabilization to spacecraft in the engineering application of high-resolution remotesensing satellite, all-sided analyses of dynamic performance induced by variousmicro-vibration resources during satellites working period. Under this background, withthe utilization of the finite element method (FEM), this thesis completes the dynamicmodeling of bus of high-resolution remote sensing satellite and the dynamic responseanalyses. The main contents are listed as follow:1. Based on the related researches on the feature of micro-vibration, it is decided toimplement the dynamic modeling and analyses of bus of high-resolution remote sensingsatellite with the FEM. A bus of remote sensing satellite is treated as the object ofresearch. With the use of FEM software, the finite element model of the bus is modeled.Based on the related methods on the mesh size of FEM, the mesh size which reaches therequirement of dynamic analyses of micro-vibration is calculated. The mesh size canmake the model valid.2. The theories of FEM real-mode analysis and frequency-response analysis arebriefly presented and applied to the FEM model of satellite’s bus. The modal andvibration-transfer characteristic of the model can be obtained.3. The theories of time-domain analysis, stochastic analysis are presented. Settingthe experimental data of a certain control moment gyroscope(CMG) as themicro-vibration resource, the disturbance response analysis is conducted to the FEMmodel of the bus. Applying the time-domain disturbance resource to the FEM model ofthe bus, the time-domain response analysis is conducted using MSC.Nastran and themean square deviation of the stable state response can be obtained statistically. Then,with usage of MSC.Nastran, the stochastic response analysis to the FEM model of thebus is conducted. Thus, the power spectral density (PSD) and cumulative root meansquare(CRMS) of the stochastic response can be obtained. Discussing the results of theanalysis, the micro-vibration character of the bus in terms of frequency-domain can beobtained. The cause of the key frequencies in the stochastic response can also beexplained.4. Firstly, the related theory of Lyapunov analytical method is presented. Then, thistheory is applied to the FEM model of the bus. In order to realize the Lyapunov analysis,the state space models of micro-vibration and the bus of satellite are built Then,integrate these models as the overall state space model. After solving the Lyapunovequation of the overall state space model, the root man square(RMS) of the response can be obtained. Lastly, comparing the three kinds of disturbance response analyses,these analytical methods can be verified and the applied features of these methods canbe obtained. The micro-vibration dynamic features getting from these analyses havevery good reference value to the researches of micro-vibration isolation and control.