Anti-Unwinding Attitude Control of Spacecraft with Forbidden Pointing Constraints

A new algorithm is proposed for rigid spacecraft attitude reorientation guidance under forbidden pointing constraints. Specifically, in view of the parameterized forbidden orientations using the unit quaternion, a special potential function is formulated for spacecraft guidance to ensure that the attitude converges to the desired attitude while avoiding pointing toward the forbidden orientations. Based on the explicit incorporation of an anti-unwinding attitude error function as a component of this potential function, the redundancy that is naturally associated with the quaternion representation is shown to have no adverse impact upon convergence to the global minima. Saliently, the unwinding phenomenon allows for automatically choosing the closer equilibrium. Analysis is performed to establish the existence of the potential field’s critical points, and a solution is given to avoid them for any given initial configuration. Numerical simulations are performed to illustrate the effectiveness and performance...