Optimal attitude control for three-axis stabilized flexible spacecraft

This paper studies the active optimal attitude control of a three-axis stabilized flexible spacecraft by flywheels. Without neglecting the second order terms in the model of attitude dynamics, the flexible spacecraft with vibration solar arrays is a nonlinear system. The nonlinear system is recursively approximated as a sequence of linear and time-varying systems, and the corresponding time-varying linear quadratic regulators (LQR) are designed for the approximated systems, so that a given optimization criterion is minimized. The results of numerical simulation show that the time-varying LQR designed gives satisfactory results in attitude maneuver and vibration suppression control for the nonlinear flexible spacecraft.