Patent ID: 6128556
Filing Date: 2000-10-03
Classification: B25J,B64G

Abstract:
A satellite attitude control comprising a plurality of control moment gyros, an attitude control comprising signal processing means for providing a gimbal angle signal, for each control moment gyro, to operate an actuator to rotate each control moment gyro to change the attitude of the satellite wherein:the signal processing means comprises:means for receiving a first signal representing a desired satellite attitude;means for receiving a second signal representing actual satellite attitude;means for producing an attitude error signal from said first and second signals;means for receiving said attitude error signal and producing a desired gimbal angle for a control moment gyro with one of a first, second or third values:the first value being the desired gimbal angle if a stored angular momentum for the desired gimbal angle is less than a predetermined singularity free producing value;the second value being an interpolation between the singularity free value and a maximum angular momentum value representing the maximum available angular momentum if the stored angular momentum for the desired gimbal angle is between said saturation free value and said maximum angular momentum value; and the third value being said maximum angular momentum value for the desired angle if the stored angular momentum for said desired gimbal angle is greater than said maximum angular momentum value.