초록 ▼

Momentum wheel speed correction in an orbital space vehicle that corrects for the oscillation resulting from spurious variations in the angular velocity of the momentum wheel. The momentum wheel's angular velocity is subject to random fluctuations due to Coulomb forces. These fluctuations are couple

Momentum wheel speed correction in an orbital space vehicle that corrects for the oscillation resulting from spurious variations in the angular velocity of the momentum wheel. The momentum wheel's angular velocity is subject to random fluctuations due to Coulomb forces. These fluctuations are coupled into the vehicle's spin rate causing errors in the yaw rate and yaw. By adding corrective values to the determined yaw rate and yaw by selectively filtering the momentum wheel tachometer signals, pointing errors are substantially reduced or even eliminated.

대표청구항 ▼

[ What is claimed is:] [7.] A programmable apparatus for correcting velocity variation errors in an on-board momentum wheel that are coupled into the spin rate of an orbiting space vehicle comprising, in combination:tachometer means coupled to the momentum wheel for supplying signals representative

[ What is claimed is:] [7.] A programmable apparatus for correcting velocity variation errors in an on-board momentum wheel that are coupled into the spin rate of an orbiting space vehicle comprising, in combination:tachometer means coupled to the momentum wheel for supplying signals representative of the motion of the momentum wheel;means for determining space vehicle attitude values;program execution means receptive of signals from the determining means representing space vehicle attitude values such as space vehicle yaw and yaw rate, and the tachometer means representing values of the motion of the momentum wheel; andcontrol program means includingmeans for modeling a filter that passes a band of frequencies which includes error-producing fluctuations in the momentum wheel's angular velocity for producing values representative of the magnitude of errors in the angular velocity of the momentum wheel,means for applying values from the modeling means to the space vehicle determined yaw rate values, andmeans for outputting from the applying means a corrected space vehicle yaw rate value; reby errors in the determined yaw rate of the space vehicle caused by momentum wheel errors are eliminated or substantially reduced.