초록 ▼

Roll and yaw attitude control method for a satellite stabilized about its roll, yaw and pitch axes embodying a momentum wheel system generating a continuous angular momentum substantially parallel to the pitch axis and having a variable component at least approximately parallel to the roll-yaw plane

Roll and yaw attitude control method for a satellite stabilized about its roll, yaw and pitch axes embodying a momentum wheel system generating a continuous angular momentum substantially parallel to the pitch axis and having a variable component at least approximately parallel to the roll-yaw plane and a continuously acting actuator system in which the roll and/or yaw attitude of the satellite is sensed. Control signals are applied to the momentum wheel system that are produced by a fast control loop using a known fast control law and second control signals are applied to the continuously acting actuator system that are produced by a slow control loop using a known slow control law. The continuously acting actuator system is loaded in fixed direction of the satellite parallel to the variable component if the latter has a fixed direction. At least a first additional control signal is applied to the momentum wheel system, chosen to yield a value of the fixed direction component of the angular momentum adapted to compensate in the long term drift of a second fixed direction component of the angular momentum. A second additional control signal is applied to the continuously acting actuator system that is adapted to cancel the effect of the first signal on the attitude with respect to the second fixed direction.

대표청구항 ▼

In a method of roll and yaw attitude control for controlling the attitude of a satellite stabilized about roll, yaw and pitch axes, wherein a single direction continuously acting actuator system generates torques along a first satellite fixed direction and a momentum wheel system generates continuou

In a method of roll and yaw attitude control for controlling the attitude of a satellite stabilized about roll, yaw and pitch axes, wherein a single direction continuously acting actuator system generates torques along a first satellite fixed direction and a momentum wheel system generates continuously non-null angular momentum having a major torque component parallel to said pitch axis and at least one variable torque component parallel to said first satellite fixed direction, the improvement of said attitude control method comprising the steps of: sensing a roll and/or yaw attitude condition; sensing a wheel speed condition from said momentum wheel system; generating from said sensed attitude condition a first wheel torque control signal along at least said first satellite fixed direction for short-term compensation of attitude errors; calculating from said sensed attitude condition and said sensed wheel speed condition a reference value for at least one variable component of said angular momentum for long-term compensation of a drift of said angular momentum along a second satellite fixed direction; generating a first additional wheel torque control signal along at least said first satellite fixed direction for long-term compensation of the error between the instant value of said at least one variable component of said angular momentum parallel to said first satellite fixed direction and said reference value; generating from said sensed attitude condition and from said sensed wheel speed condition second wheel torque control signals along said first satellite fixed direction for long term compensation of attitude errors and disturbing torques; generating second additional wheel torque control signals along said first satellite fixed direction for compensation of the effect of said first additional torque control signals on satellite attitude along said second satellite fixed direction; generating first control commands from said first wheel torque control signals and said first additional wheel torque control signals and applying said first control commands to said momentum wheel system; and generating second control commands from said second wheel torque control signals and said second additional wheel torque control signals and applying said second control commands to said single direction continuously acting actuator system.