Study On Performance Simulation And Optimal Control Of Momentum Flywheel Isolation Platform

Large satellite with high resolution for earth observation and astronomicalobservation recently became a significant trend in space development. The accuracyrequirement of space optical payload becomes higher, and effects of all kinds ofvibration source are more obvious, especially the vibration induced in the process ofspacecraft launching and attitude adjustment would cause continuous disturbance withwidely distributed frequency band. To reduce the influence of vibration and providesatellite with “extra-static” mechanical environment, the most effective method is toinstall vibration isolator in satellite.In this paper, combining theoretical modeling with simulation analysis,performance simulation and optimal control of momentum flywheel isolation platformwere studied on the basis of the weapon equipment pre-research key fund project[9140A2011QT4801], the main work and innovative points of the paper are as follows:(1) Dynamic characteristics analysis of passive vibration, active vibration andcombining active with passive vibration isolation systems was done. The analysedresults showed that low and medium frequency vibration on satellite could not beisolated by using passive vibration isolation only. The best isolation effect is a directeffect of the actuator on the isolation object. The selection of control law, feedbackvariable and feedback gain is critical for isolation performance.(2) The cube structure Stewart vibration isolation platform which put isolationinto practice in six directions was designed, and Newton-Euler method was used todeduce dynamic model of vibration isolation platform. Based on MATLAB/Simulinkand ADAMS, dynamic simulation system and the virtual prototype model of vibrationisolation platform were built. The simulation results indicates that the amplitude ofvibration response was reduced from6×10-6rad/s to2×10-7rad/s, which illustrate thatvibration isolation platform played a positive role in attitude stability of the wholesatellite.(3) By comparative analysis of LQ optimal and PID control system, a method forPID parameter optimazing was obtained and applied in the active control system. Theco-simulation results of MATLAB and ADAMS show that the optimized system has asatisfactory effect on vibration isolation, and vibration amplitude reduce one order ofmagnitude, which present a high precision isolation of spacecraft.