Attitude controllers for spacecraft have been based on the assumption that the bodies being controlled are rigid. Future spacecraft, however, may be quite flexible. Many applications require spinning up/down these vehicles. In this work the minimum time control of these maneuvers is considered. The time-optimal control is shown to possess an important symmetry property. Taking advantage of this property, the necessary and sufficient conditions for optimality are transformed into a system of nonlinear algebraic equations in the control switching times during one half of the maneuver, the maneuver time, and the costates at the mid-maneuver time. These equations can be solved using a homotopy approach. Control spillover measures are introduced and upper bounds on these measures are obtained. For a special case these upper bounds can be expressed in closed form for an infinite dimensional evaluation model. Rotational stiffening effects are ignored in the optimal control analysis. Based on a heuristic argument a simple condition is given which justifies the omission of these nonlinear effects. This condition is validated by numerical simulation.
Time-optical spinup maneuvers of flexible spacecraft
1990-03-01
Sonstige
Keine Angabe
Englisch
Spinup Dynamics of Axial Dual-Spin Spacecraft
Online Contents | 1994
|Dual-Spin Spacecraft Dynamics During Platform Spinup
AIAA | 1980
|Spinup dynamics of axial dual-spin spacecraft
AIAA | 1994
|