Spacecraft off-gimbal IRU precision payload pointing and disturbance rejection system
AssigneeThe Aerospace Corporation
InventorsRobert Wong, Jason Ly, Philip Dahl, Arthur Or
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Abstract
An off-gimbal pointing system is improved using filtering of resolver and gyro responses respectively applied at the output of the resolvers and gyros for attenuating high frequencies resolver responses and gyro responses that effectively degrades the high frequency responses that are matched and above the control system bandwidth for improving the overall dynamic control of the off-gimbal pointing system for rejecting the affects of base motion disturbances and vibrations.
Claims13
A pointing system for pointing a boresight along a desired line-of-sight in response to a command to point the boresight along the desired line-of-sight, the system comprising,
- a base for providing a platform and for coupling base motion and line-of-sight motion of the boresight for providing a mechanical excitation,
- a gimbal system comprising an elevation gimbal and an azimuth gimbal for positioning a boresight along the desired line-of-sight relative to the base, the elevation gimbal and the azimuth gimbal are modeled by a plant, the elevation gimbal and the azimuth gimbal comprise a suspension modeled by a compliance receiving the mechanical excitation and providing a compliance signal, the elevation gimbal and the azimuth gimbal are controlled by a torque signal being a sum of a compliance signal and a drive signal,
- a resolver system comprising an elevation resolver and an azimuth resolver for respectively measuring as resolver responses a relative elevation angle and a relative azimuth angle of the boresight relative to the base,
- a resolver filter system for resolver filtering of the resolver responses for providing a filtered resolver response, the mechanical excitation being applied to the resolver system for providing the resolver responses,
- a gyro system comprising X and Y and Z gyros for measuring as gyro responses X and Y and Z angular rates of the base motion,
- a gyro filter for gyro filtering of the gyro responses for providing filtered gyro respons s, and
- a controller comprising gimbal motors for receiving a control input and providing motion control to the elevation gimbal and the azimuth gimbal, the control input signal being a sum of the command and the filtered resolver responses and the filtered gyro responses.
A pointing system for pointing a boresight along a desired line-of-sight in response to a command to point the boresight along the desired line-of-sight, the system comprising,
- a base for providing a platform and for coupling base motion and line-of-sight motion of the boresight for providing a mechanical excitation,
- a gimbal system comprising an elevation gimbal and an azimuth gimbal for positing a boresight along the desired line-of-sight relative to the base, the elevation gimbal and the azimuth gimbal are modeled by a plant, the elevation gimbal and the azimuth gimbal comprise a suspension modeled by a compliance receiving the mechanical excitation, the elevation gimbal and the azimuth gimbal are controlled by a torque signal being a sum of a compliance signal from the modeled compliance and a drive signal,
- a gyro system comprising X and Y and Z gyros for measuring as gyro responses the X and Y and Z angular rates of the base having the base motion,
- a gyro filter for gyro filtering of the gyro responses for providing filtered gyro responses,
- a controller comprising gimbal motors for receiving a control input and providing motion control to the elevation gimbal and the azimuth gimbal, the control input signal being a sum of the command and the filtered gyro responses.
A pointing system for pointing a boresight along a desired line-of-sight in response to a command to point the boresight along the desired line-of-sight, the system comprising,
- a base for providing a platform and for coupling base disturbances to the line-of-sight of the boresight for providing a mechanical excitation,
- a gimbal system comprising an elevation gimbal and an azimuth gimbal for positing a boresight along the desired line-of-sight relative to the base, the elevation gimbal and the azimuth gimbal are modeled by a plant, the elevation gimbal and the azimuth gimbal comprise a suspension modeled by a compliance receiving the mechanical excitation, the elevation gimbal and the azimuth gimbal are controlled by a torque signal being a sum of a compliance signal from the modeled compliance and a drive signal,
- a resolver system comprising an elevation resolver and an azimuth resolver for respectively measuring a relative elevation angle and a relative azimuth angle of the boresight relative to the base as resolver responses,
- a resolver filter system for resolver filtering of the resolver responses for providing a filtered resolver response, the mechanical excitation being applied to the resolver system for providing the resolver responses,
- a controller comprising gimbal motors for receiving a control input and providing motion control to the elevation gimbal and the azimuth gimbal, the control input signal being a sum of the command and the filtered resolver responses.
Dependencies are inferred from the claim text.