NEAR-MINIMUM TIME, CLOSED-LOOP SLEWING OF FLEXIBLE SPACECRAFT

The near-minimum time single-axis slewing of a flexible spacecraft with simultaneous suppression of vibration of elastic modes is considered. The hyperbolic tangent (tahh) function is used as a smooth approximation to the discontinuous sgn function occurring in the rigid body "bang-bang" control. Variable structure control concepts are used to identify the necessary characteristics of the control switching line. Simulations of the rest-to-rest and tracking maneuvers indicate that the elastic energy can be reduced by several orders of magnitude with only a modest increase in the maneuver time. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.