Dynamic parameter identification of damping reinforced components and its application in space optical instrument stabilization

Abstract

Damping reinforced components is an efficient way to improve the pointing stability of optical instrument. Traditionally, modeling methods of damping reinforced components are mostly based on simple load test data, such as time domain method or half power band width method. Modeling methods based on response under static load or dynamic load at a certain frequency cannot cover the dynamic characteristic in a wide frequency range. An experimental modeling method of damping reinforced components in wide frequency band was presented and its effect in optical structures was evaluated based on the model. First, a cantilever beam of damping reinforced component was excited in a sine sweep test to get its frequency response. A parametric viscous damping model was proposed and the frequency response was solved with Laplace transform. Then, the parameters were identified by solving an unconstrained optimization problem with pattern search method, which minimized the deviation between test result and calculated result by least square criteria. Finally, the pointing stability of a typical optical structure adopting damping reinforced components was analyzed based on the derived dynamic model, which indicated that the line of sight jitter was attenuated because of the absorption of vibration energy by damping reinforced components.