Decentralized slew maneuver control of large flexible spacecrafts

The control problem of slewing maneuvers of a class of large flexible spacecrafts is developed. The example of the Spacecraft Control Laboratory Experiment is used to design control systems for the combined problem of rigid-body slew maneuver and vibration suppression of a flexible appendage. The control problem is formulated based on a nonlinear dynamical model of an arbitrary large-angle slew maneuver. This formulation is expressed in terms of a two-point boundary-value problem utilizing a quadratic type of performance index. The two-point boundary-value problem is solved as a decentralized control problem with the overall system being split in terms of two subsystems, namely, the slewing of the entire assembly and the vibration suppression of the flexible antenna. The coupling variables between the two dynamical subsystems are treated independently in parallel at one level for control purposes. The state-space trajectory of the combined problem is then optimized at the second level