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AssigneeEADS Astrium GmbH
InventorsKristen Lagadec, Ange Defendini
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In order to control the attitude of a satellite having at least four gyroscopic actuators with respective spinners mounted on gimbals steerable about axes parallel to one or the other of only two different directions that are fixed relative to the satellite, the attitude of the satellite is measured using sensors on board the satellite, the control torque required to perform an attitude-changing maneuver is calculated, local linearization calculation is performed based on pseudo-inversion of the Jacobean matrix of the function associating the orientations of the actuator gimbals with the total kinetic moment of the cluster in order to determine a new gimbal orientation, and precession speeds of at least one of the gimbals of the actuators is controlled to deliver the control torque for reaching the desired configuration. The calculation is performed while applying a constraint of seeking a cluster configuration that is remote from singular configurations by sharing between the two groups of actuators that component of the total kinetic moment of the cluster which is perpendicular to both of the two directions.
A method of controlling the attitude of a satellite having a cluster of at least four gyroscopic actuators with respective spinners mounted on gimbals steerable about axes parallel to one or the other of only two different directions that are fixed relative to the satellite, the method comprising the steps of:
A method according to any preceding claim for controlling the satellite in application of a relationship that is determined over time, the method being characterized in that a final configuration remote from singularities is sought continuously by permanently deflecting the cluster configuration so as to occupy the local maximum of the distance-from-singularity criterion.
Dependencies are inferred from the claim text.