Robust switching of modified rodrigues parameter sets for saturated global attitude control

the global attitude control of a rigid spacecraft based on the two modified rodrigues parameter (MRP) sets is approached in the framework of hybrid systems. A hybrid proportional-derivative (PD) feedback controller for attitude stabilization is proposed by incorporation of a MRP switching logic. The switching surface is specified by a sphere of radius in the MRP space. The hybrid attitude controller is independent of the rigid-body inertia and ensures a priori bounded control torques, which allows accommodation of saturation constraints and simultaneous robustness to measurement noise which is measured by the hysteresis constant.