Spacecraft Anti-Unwinding Attitude Control with Actuator Nonlinearities and Velocity Limit

摘要

A nonlinear feedback control logic is developed for spacecraft attitude stabilization subject to various physical constraints that often occur in practical aerospace applications, such as actuator saturation, dead-zone nonlinearities, and velocity limits, in the presence of parametric uncertainty and external disturbances. Unlike other control methods, the approach presented here provides a truly global result backed up by a complete stability proof. The angular velocity is also guaranteed to be bounded and vanishes in the presence of the external disturbance regardless of the parameter selections or features of the maneuver. The poor performance caused by the actuator dead-zone nonlinearity and the external disturbance can be overcome by the user-defined adaptive functions. The controller is inertia-free and does not need any information about the actuator dead-zone nonlinearity. In addition, our adoption of a new attitude error vector plays a crucial role in solving the unwinding problem. Numerical simulations illustrate the improved spacecraft performance obtained using the proposed controller.