Angular momentum management of space station based on pole placement

For the problem that gravity-gradient torque and other disturbance torques can cause the accumulation of control momentum gyros (CMG) angular momentum when space station operates in inertial frame. Gravity-gradient torque is used for torque equilibrium attitude. An angular momentum management controller based on pole placement is proposed. First, the linearized model of space station in inertia frame is established and the infeasibility of the pitch axis direction of angular momentum management is proved. So we decouple the pitch axis and the roll/yaw axis, and do not constrain the angular momentum of CMG in pitch axis. The disturbance rejection filters are introduced to suppress the disturbance's impact on attitude in pitch axis. In orbit plane, to limit the cyclic disturbance's impact on roll/yaw axis and the secular disturbance's impact on the angular momentum of CMG, other disturbance rejection filters are introduced. Then, feedback controllers in pitch and row/yaw axis are developed based on linear quadratic regulators (LQR) with pole placement respectively. This algorithm is developed to place the closed-loop poles to the left side of complex plane imaginary axis based on the system performance requirements without choosing weight matrix. Finally, the simulation results demonstrate the validity of the proposed algorithm.