Bias Momentum Attitude Control System Using Energy/Momentum Wheels

The integrated power and attitude control for a bias momentum attitude control system is investigated. A pair of counter spinning wheels is used to provide the bias angular momentum and store/discharge energy for power requirement of the devices on the spacecraft. The roll/yaw motion is controlled by pitch magnetic dipole moment. The torque based control law of the wheels is designed, so that the desired pitch control torque is provided and the operation of charging/discharging energy is carried out based on the given power. System singularity in the control law of wheels is fully avoided by keeping the wheels counter spinning. A power management scheme using kinetic energy feedback is proposed to keep energy balance, which can avoid wheel saturation caused by superfluous energy. The minimum moment of inertia of the wheels is limited by the maximum bias angular momentum and the minimum energy, such constrains are analyzed in combination with the geometrical method. Numerical simulation results are presented to demonstrate the effectiveness of the control scheme.