Time-Optimal Attitude Control of an Axially Symmetric Spinning Spacecraft

摘要

This report considers the problem of controlling both the attitude and angular velocities of an axially symmetric spacecraft while minimizing the maneuver duration. In particular, various combinations of thrust limited reaction jets are employed to properly orient a spinning space body with respect to specified reference directions starting from known initial conditions of the vehicle's attitude and angular rates. Five control jet configurations are considered: two gimballed systems where torques can be applied about, (1) any axis in a plane normal to the axis of symmetry, (2) two perpendicular non-rotating axis in a plane normal to the axis of symmetry; and three body-fixed configurations where the thrusters are immobile relative to the vehicle and can provide both positive and negative or only positive (negative) control torques about one or both of the vehicle's transverse axis. The control systems are realizable from a hardware standpoint and the corresponding optimal controls can be classified as: (1) a continuous function of time, (2) bang-bang, (3) on-off, and (4) a combination of (1 and 2) or (2 and 3). (Author)