초록 ▼

The estimation and compensation of fixed, but unknown uncertainties of a thruster (22) for improving satellite attitude estimation and control as well as eliminating the need for nutation damping devices is disclosed. A thruster (22) is fired and an attitude state is estimated using an estimator (11

The estimation and compensation of fixed, but unknown uncertainties of a thruster (22) for improving satellite attitude estimation and control as well as eliminating the need for nutation damping devices is disclosed. A thruster (22) is fired and an attitude state is estimated using an estimator (116). A commanded rate change (122) is calculated, which is modified using a compensating feedforward command (126) as updated by a fixed uncertainty estimator (124) unless an estimated rate is less than an absolute value of a threshold rate. The modified commanded rate change (130) is used to incrementally adjust thruster fire on-time (104) until a predetermined satellite trajectory is reached.

대표청구항 ▼

For use with a satellite having thrusters, a method for moving a probability distribution for thruster on-time from a fixed bias offset to one with no bias, comprising the steps of: (A) firing a thruster of a satellite; (B) estimating an attitude state; and (C) compensating for a fixed thruster on-t

For use with a satellite having thrusters, a method for moving a probability distribution for thruster on-time from a fixed bias offset to one with no bias, comprising the steps of: (A) firing a thruster of a satellite; (B) estimating an attitude state; and (C) compensating for a fixed thruster on-time uncertainty by adjusting a compensating feedforward command using a rate equivalent to a fixed period of thruster on-time for each said firing of said thruster until said probability distribution is substantially within a desired target region wherein there is no said fixed bias offset.