Coupling⁃Reduced Optimal Placement of Piezoelectric Actuators for Spacecraft with Flexible Telescope

The oscillation of large space structure（LSS）can be easily induced because of its low vibration frequency. The coupling effect between LSS vibration control and attitude control can significantly reduce the overall performance of the control system，especially when the scale of flexible structure increases. This paper proposes an optimal placement method of piezoelectric stack actuators（PSAs）network which reduces the coupling effect between attitude and vibration control system. First，a spacecraft with a honeycomb-shaped telescope is designed for a resolution-critical imaging scenario. The coupling dynamics of the spacecraft is established using finite element method （FEM）and floating frame of reference formulation（FFRF）. Second，a coupling-effect-reducing optimal placement criterion for PSAs based on coupling-matrix enhanced Gramian is designed to reduce the coupling effect excitation while balancing controllability. Additionally，a laddered multi-layered optimizing scheme is established to increase the speed and accuracy when solving the gigantic discrete optimization problem. Finally，the effectiveness of the proposed method is illustrated through numerical simulation.