Methods and systems for imposing a momentum boundary while reorienting an agile vehicle with control moment gyroscopes
AssigneeHoneywell International Inc.
InventorsBrian Hamilton, Brian Underhill
Life of this patent
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Abstract
Methods and systems are provided for reorienting an agile vehicle, such as a satellite or spacecraft, using a control moment gyroscope (CMG) array. The CMG array comprises a plurality of CMGs onboard the agile vehicle. A method comprises obtaining an input torque command for reorienting the vehicle using the CMG array and, when the angular momentum of the CMG array violates or is approaching a momentum boundary criterion, decreasing the input torque command in the kinetic momentum direction, resulting in a modified torque command, and operating the CMG array using the modified torque command.
Claims21
A method for reorienting a vehicle using a control moment gyroscope (CMG) array comprising a plurality of CMGs onboard the vehicle, the CMG array having a total angular momentum including a kinetic angular momentum component in a kinetic momentum direction, the method comprising:
- obtaining an input torque command for reorienting the vehicle using the CMG array;
- and
- when the total angular momentum violates or is approaching a momentum boundary criterion:
- decreasing the input torque command in the kinetic momentum direction, resulting in a modified torque command;
- and
- operating the CMG array using the modified torque command.
A method for controlling attitude of an agile vehicle using a plurality of gyroscopes onboard the agile vehicle, the method comprising:
- receiving an input torque command vector for adjusting attitude of the agile vehicle;
- obtaining a total momentum vector corresponding to total angular momentum of the plurality of gyroscopes in a momentum direction, the total momentum vector including a kinetic momentum component in a kinetic momentum direction;
- determining whether the total angular momentum of the plurality of gyroscopes exceeds or is likely to exceed a limit on momentum in the momentum direction imposed by a steering control law for operating the plurality of gyroscopes prior to stopping rotation of the plurality of gyroscopes;
- reducing a component of the input torque command vector in the kinetic momentum direction, resulting in a modified torque command vector;
- and
- operating the plurality of gyroscopes based on the modified torque command vector and the steering control law.
A control system for an agile vehicle, the control system comprising:
- an attitude control system (ACS) configured to provide a torque command for reorienting the agile vehicle;
- and
- a momentum control system (MCS) coupled to the ACS, the MCS comprising a control moment gyroscope (CMG) array comprising a plurality of CMGs onboard the agile vehicle, wherein the MCS is configured to:
- obtain the torque command from the ACS;
- identify when angular momentum of the CMG array violates or is approaching a momentum boundary criterion;
- and
- when the angular momentum of the CMG array violates or is approaching the momentum boundary criterion:
- determine a modified torque command by decreasing the torque command in a direction of kinetic angular momentum of the CMG array;
- and
- operating the CMG array using the modified torque command.
A method for reorienting a vehicle using a control moment gyroscope (CMG) array onboard the vehicle, the CMG array having a total angular momentum including a kinetic angular momentum component in a kinetic momentum direction, the method comprising:
- obtaining an input torque command for reorienting the vehicle using the CMG array;
- and
- when the total angular momentum violates or is approaching a momentum boundary criterion:
- subtracting a projection of the input torque command onto a unit vector in the kinetic momentum direction from the input torque command to obtain a modified torque command;
- and
- operating the CMG array using the modified torque command.
Dependencies are inferred from the claim text.