초록 ▼

A method for simultaneously controlling satellite nutation, sun angle and attitude walk using a dual-slit sun sensor and thrusters. The sun angle and nutation angles are computed from sun sensor data, and the thrusters are fired when their use improves both sun angle and nutation. Precession around

A method for simultaneously controlling satellite nutation, sun angle and attitude walk using a dual-slit sun sensor and thrusters. The sun angle and nutation angles are computed from sun sensor data, and the thrusters are fired when their use improves both sun angle and nutation. Precession around the sun line is controlled by constraining firing, in the simplest case, firing only when the angular momentum is precessed directly toward or away from the sun. Precession maneuvers are implemented by commanding a new sun angle and precession plane spin phase.

대표청구항 ▼

[ What is claimed is:] [1.] A method for simultaneously controlling precession and nutation of a satellite capable of spinning about a spin axis and nutating about an angular momentum vector, the satellite including at least one thruster whose precession torques have a known spin phase with respect

[ What is claimed is:] [1.] A method for simultaneously controlling precession and nutation of a satellite capable of spinning about a spin axis and nutating about an angular momentum vector, the satellite including at least one thruster whose precession torques have a known spin phase with respect to at least one stationary reference relative to the satellite, the satellite also including a dual-slit sun sensor having a straight slit sensor and a canted slit sensor, the method comprising:obtaining spinning measurements of the at least one reference by sensing solar times of arrival at the straight slit sensor and the canted slit sensor;computing nutation and precessing angles from the spinning measurements bycomputing satellite spin phase from straight slit times of arrival,determining elapsed time between solar times of arrival at the straight and the canted slit sensors,computing instantaneous sun elevation from the elapsed time between solar times of arrival at the straight and the canted slit sensors, anddetermining satellite precession and nutation from the sun elevation; andfiring the at least one thruster when positioned to limit nutation and precessing error to acceptable levels while driving them to desired states thereof.