B - Operations – Transporting – 64 – G
Patent
B - Operations, Transporting
64
G
341/80
B64G 1/24 (2006.01) B64G 1/28 (2006.01) B64G 1/36 (2006.01) G05D 1/08 (2006.01)
Patent
CA 1196075
DIGITAL PWPF THREE AXIS SPACECRAFT ATTITUDE CONTROL Abstract A digital system for controlling the attitude of a spacecraft (14), e.g., a satellite, with respect to three orthogonal axes. The system can control satellites (14) in parking orbit, transfer orbit, or final operational orbit, whether or not the satellite (14) employs one or more momentum wheels. A processor (2) converts weighted data from spacecraft sensors (12), representing angular orientation and angular velocities about each of the three axes, into thruster pulsetrain signatures to command the firing of each of six thrusters positioned about spacecraft (14), a positive and a negative thruster being positioned to impart both directions of angular momentum about each of the three axes. Each thruster pulsetrain signature is created once every processed error cycle period T1, and contains a varying number of pulses of varying widths. A negative feedback PWPF loop (2, 16, 20, 22, 24) is actuated for each of the three axes, preferably several times each T1 in order to achieve better thruster on/off resolution. The PWPF loops are preferably implemented by digital means. Serial-out shift registers (44, 46) load the thruster pulsetrain signatures into means (48, 50, 52, 54) for firing the thrusters, preferably after splitting the signature pulses into clone pulses in order to minimize the impact of errors due to asynchronization between the clock which loads the registers (44, 46) and the clock which shifts these registers. Data extenders (40, 42) eliminate possible gaps caused by asynchronization, and thus prevent unwanted on/off thruster switching.
433068
Chan Fred N.
Nilsen Frank C.
Ford Aerospace & Communications Corporation
Gowling Lafleur Henderson Llp
LandOfFree
Digital pwpf three axis spacecraft attitude control does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digital pwpf three axis spacecraft attitude control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital pwpf three axis spacecraft attitude control will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1217853