Attitude control system complexity reduction via tailored viscoelastic damping co-design

Intelligent structures utilize distributed actuation, such as piezoelectric strain actuators, to control flexible structure vibration and motion. A new type of intelligent structure has been introduced recently for precision spacecraft attitude control. It utilizes lead zirconate titanate (PZT) piezoelectric actuators bonded to solar arrays (SAs), and bends SAs to use inertial coupling for small-amplitude, high-precision attitude control and active damping. Integrated physical and control system design studies have been performed to investigate performance capabilities and to generate design insights for this new class of attitude control system. Both distributedand lumped-parameter models have been developed for these design studies. While PZTs can operate at high frequency, relying on active damping alone to manage all vibration requires high-performance control hardware. In this article we investigate the potential value of introducing tailored distributed viscoelastic materials within SAs as a strategy to manage higher-frequency vibration passively, reducing spillover and complementing active control. A case study based on a pseudo-rigid body dynamic model (PRBDM) and linear viscoelasticity is presented. The tradeoffs between control system complexity, passive damping behavior, and overall dynamic performance are quantified.