Hybrid stabilization of controlled spacecraft

We present several switching controllers for the attitude stabilization of a spacecraft. The control laws are reminiscent of classic controllers for robot manipulators, adapted to the topology of the quaternion space, in which the model of the spacecraft is expressed. A switching law is incorporated to deal with multiplicity of equilibria, inherent to the rigid-body model. Another controller based on a hysteresis supervisor is presented. This may be seen as a switching controller which commutes between two switching controllers. Detailed simulation results are also included where the emphasis is put into an adequate tunning; in particular, it is showed that with an appropriate switching law one may significantly decrease fuel consumption which directly translates into spacecraft lifespan.