Attitude control for large angle maneuvers

A sliding manifold based control strategy is proposed for the attitude control problem. By using the theory of singular perturbation and the globally nonsingular unit quaternion representation for the orientation error a nonlinear feedback control is designed. The use of quaternions allows us to avoid the drawbacks of Euler angle approach, namely singularities which can occur in large maneuvers. The feedback control system exhibits robustness properties with respect to disturbances and plant parametric uncertainties. The resulting control signal remains, after a fast transient, in a neighborhood of the well-defined equivalent control avoiding the peaking phenomenon of high gain systems. The proposed control technique is then applied to a complete satellite rotation about a fixed axis