Research On Micro-vibration Semi-active Vibration Isolation Technology For Optical Remote Sensing Satellite

With the development of space remote sensing information in disaster control,environmental detection,military field and scientific research,remote sensing satellite technology is experiencing unprecedented development.Flywheel,as an important actuating component to guarantee attitude control of optical remote sensing satellite,will generate small amplitude,wide bandwidth disturbance force and moment during its normal operation.Although these disturbing forces and moments will not destroy the structure,they may cause the relative position accuracy of sensitive optical elements to be reduced and affect the imaging quality.In serious cases,they may even cause the image to be blurred,degraded,and distorted.Therefore,it is necessary to carry out indepth study on flywheel micro-vibration.Based on the high resolution optical remote sensing satellite in the constellation of Jilin No.1 satellite,the semi-active vibration isolation technology for micro-vibration is studied in this paper.The main work is summarized as follows:Firstly,a circular single-channel magnetorheological damper is designed and studied,and theoretical modeling and experimental research are carried out.Based on the constitutive characteristics of magnetorheological fluids and related dynamic theories,the theoretical model of circular single-channel magnetorheological damper is established,the structural configuration and parameters of magnetorheological damper are designed,and the accuracy of the theoretical model is verified by experiments.By comparing the numerical calculation results with the test results,it is proved that the theoretical model established in this paper is more accurate,and the MR damper with this structure is suitable for the application of semi-active vibration isolation technology for satellite micro-vibration.Then the kinematics and dynamics model of Stewart vibration isolation platform with MR damper as vibration isolation unit is established,and the accuracy of the theoretical model of the platform is analyzed and verified.In the scene of optical remote sensing satellite on-board application,the kinematic model of Stewart vibration isolation platform is established by using multi-rigid body rotating coordinate method and the dynamic model of Stewart vibration isolation platform is established by using Newton-Euler method.The position and attitude movement characteristics and dynamic transmission characteristics of the platform are analyzed in detail,and the relationship between input disturbance and output response is clarified,which provides a reference for the design of semi-active control strategy.Then,semi-active control strategy is designed,which converts multi-input and multi-output into single-input and single-output problems based on the characteristics of Stewart vibration isolation platform.Combining the control algorithm of optimal control and fuzzy control,semi-active vibration isolation strategy is designed and semiactive control test of single-degree-of-freedom magnetorheological damper is carried out.The vibration attenuation characteristics of magnetorheological damper under semi-active closed-loop control are tested.At the level of vibration isolation unit,the suppression effect of the control algorithm is verified.Finally,the integrated modeling and performance evaluation for semi-active vibration isolation platform in on-board environment are studied.An integrated timedomain fully closed-loop integrated analysis method is proposed to study the mechanical characteristics of semi-active vibration isolation technology in space-borne environment.The method integrates the vibration source subsystem,structure subsystem,attitude control subsystem and optical subsystem models.The overall model uses the ground injection satellite adjustment attitude command as input,the timefrequency domain information of satellite optical performance index response as output,and the optical system imaging image shift as output.At the same time,the simulation analysis results in time and frequency domain are obtained.Ground test proves that the integrated modeling method can accurately analyze the micro-vibration problem and use the model to evaluate the suppression effect of semi-active vibration isolation technology on micro-vibration.The simulation results show that the semi-active vibration isolation technology studied in this paper can better suppress and attenuate the micro-vibration problem of optical remote sensing satellite flywheel.