Analysis And Test Of The Vibration Isolation Characteristics For The Vibration Isolation Unit And Platform

During working on the orbit,the spacecraft will be subject to various disturbances,such as the control moment gyroscopes,flywheels and others will lead to vibrations.These vibrations will have a greater impact on the attitude performance of the spacecraft.Especily for the spacecraft which have the high requirements of attitude accuracy and stability,such as highresolution observation satellites,laser communication satellites,these high frequency vibrations will affect the result of the payload,and even lead to laser payload cannot aim at the target,even makes the task failed.Therefore,for the vibration sources on the spacecraft,vibration isolation or vibration control is required to provide an ultra-quiet environment for the payload.In this thesis,the high frequency vibration problem on the spacecraft is focused.The dynamic characteristics of the vibration isolation device and the vibration isolation platform are analyzed.We also set up the ground test system for the single-degree-of-freedom vibration isolation unit.This thesis mainly includes the following aspects:1?The vibration isolation characteristics of single-degree-of-freedom vibration isolation devices under basic fixed conditions and basic motion are analyzed respectively.The influence mechanism of various parameters on vibration isolation elements is analyzed.In order to improve the vibration isolation effect,the vibration isolation characteristics of single degree of freedom vibration isolation devices are studied based on the PID control.2?For the nonlinear D-Strut unit and the adaptive D-Strut unit,the dynamic modeling is established considering the nonlinear damping characteristics.By using the harmonic balance method,the frequency domain characteristics of the two nonlinear struts are analyzed.In addition,the differences of the linear models and the nonlinear models for these two D-Strut are analyzed.3?The kinematic and dynamic model of the 6-DOF vibration isolation platform are derived by Newton Euler method.The passive vibration isolation effect of the vibration isolation platform is analyzed by numerical simulation.The dynamic model of the vibration isolation platform is simplified based on some reasonable assumptions,and the parameter design of the vibration isolation platform is studied.In addition,the vibration isolation performance of the isolation platform with the linear strut and with the nonlinear strut are compared and analyzed.4?The ground test system of single-degree-of-freedom vibration isolation unit is built.This test system contains vibration isolation unit,load,eddy current displacement sensor,drive control system,data acquisition system and computer.