초록 ▼

A pitch momentum stabilized spacecraft includes an earth sensor for generating roll signals. The roll signals are applied to torquers for proportional (P) or proportional-integral PI control of roll and yaw. According to the invention, the sensed roll signals are bandpass filtered at the orbit rate,

A pitch momentum stabilized spacecraft includes an earth sensor for generating roll signals. The roll signals are applied to torquers for proportional (P) or proportional-integral PI control of roll and yaw. According to the invention, the sensed roll signals are bandpass filtered at the orbit rate, phase adjusted and applied to the roll and yaw torquers for closing a high gain degenerative feedback loop at the orbit rate, which reduces orbit-rate components of roll and yaw. A second bandpass filter at the second harmonic of the orbit rate is also connected to the earth sensor, for producing second harmonic signals, which are phase controlled and summed with the fundamental orbit rate signals, for degeneration of attitude perturbations occurring at twice the orbit frequency.

대표청구항 ▼

An attitude control system for a spacecraft orbiting a heavenly body, said spacecraft being associated with pitch, roll and yaw axes, said spacecraft comprising: wheel means coupled to said spacecraft, for providing momentum bias along the pitch axis of said spacecraft; torquing means coupled to sai

An attitude control system for a spacecraft orbiting a heavenly body, said spacecraft being associated with pitch, roll and yaw axes, said spacecraft comprising: wheel means coupled to said spacecraft, for providing momentum bias along the pitch axis of said spacecraft; torquing means coupled to said spacecraft for creating control torques about at least said yaw axis of said spacecraft; roll angle sensing means coupled to said spacecraft, for generating signals representative of roll angle; first control means coupled to said roll angle sensing means and to said torquing means for providing at least proportional feedback for control of said yaw of said spacecraft; orbit rate bandpass filter means tuned to a frequency corresponding to one of the fundamental and a harmonic of the orbital rate of said spacecraft about said heavenly body, for generating an orbit rate filtered signal; and coupling means coupled to said roll angle sensing means, and to said torquing means, for forming a high gain feedback control loop by which said orbit rate filtered signals are applied to said torquing means with phase selected for reducing at least said yaw of said spacecraft.