15th Triennial World Congress of the International Federation of Automatic Control
  Barcelona, 21–26 July 2002 
GENERAL ATTITUDE CONTROL ALGORITHM FOR SPACECRAFT EQUIPPED WITH STAR CAMERA AND REACTION WHEELS
Rafaeł Wiśniewski* and Piotr Kulczycki
* Aalborg University, Department of Control Engineering, Frederik
Bajers Vej 7, DK-9220 Aalborg Ø, Denmark. raf@control.auc.dk
Polish Academy of Sciences, Systems Research Institute, Newelska 6,
PL-01-447 Warsaw, Poland. kulczycki@ibspan.waw.pl

A configuration consisting of a star camera, four reaction wheel and magnetorquers for momentum unloading has become standard for many spacecraft missions. This popularity has motivated numerous agencies and private companies to initiate work on the design of an imbedded attitude control system realized on an integrated circuit. This paper provides an easily implementable control algorithm for this type of configuration. The paper considers two issues: slew maneuver with a feature of avoiding direct exposure of the camera’s CCD chip to the Sun and optimal control torque distribution in a reaction wheel assembly. The attitude controller is synthesized applying the energy shaping technique, where the desired potential function is carefully designed using a physical insight into the nature of the problem. The system stability is thoroughly analyzed and the control performance simulated.
Keywords: Attitude control, satellite control, energy control, quaternion feedback
Session slot T-Tu-A06: Space Craft and Missile Control/Area code 8a : Aerospace