Exact nonlinear control of large angle rotational maneuvers

The rigid body attitude control problem with external torques is transformed into an equivalent linear form implementable by three double integrators. The linearizing transformations themselves are formulated in vector algebra, requiring no integrators for implementation. It is thereby shown that optimal command generation for fast slewing maneuvers can be carried out exactly in the transformed system, together with regulator design without gain scheduling for correction of unmodeled disturbances. In particular, a general rest-to-rest maneuver is computed in closed form, and coupled with a previously obtained exact detumbling maneuver so that arbitrary initial conditions can be accommodated. An illustrative simulation is appended.