Reducing jitter during large slews using multifunctional structures for attitude control via torque analysis

Multifunctional Structures for Attitude Control (MSAC) are a class of new attitude control systems that utilize intelligent flexible deployable panels as attitude control actuators. Spacecraft attitude is modified via a repeated cycle of deformations achieved using embedded distributed strain actuators. Previously, MSAC has demonstrated the ability to rotate about a given axis for arbitrarily-large angles using non-holonomic control trajectories. Large attitude slews are achieved by oscillating the panels about two different axes, thereby modifying the mass moment of inertia between different phases of motion. Most control trajectories developed thus far have been based on dynamical models developed using conservation of angular momentum. In this article, the MSAC system model is developed using a torque interaction model, which is then used to design control trajectories that expand system operational envelopes and the pointing stability during slews. This paper concludes with simulation-based validation of the mechanical and control design of the MSAC system that improves system performance by reducing the vibrations introduced during attitude slews by almost 40 dB and increases the operational frequencies to beyond the first harmonic of the deployable panel.