Active fault-tolerant satellite attitude control based on fault effect classification

An active fault-tolerant satellite attitude control scheme based on fault effect classification is presented at the occurrence of faults associated with torques. In this paper, the flexibility and practicability of the fault-tolerant scheme are top priorities. Faults are modeled and divided into additive and multiplicative ones in order to estimate and deal with them specifically and exactly. The additive faults, including additive part of flywheel faults and other uncertain fault torques, are estimated by additive fault estimator and compensated on the basis of nominal controller, whereas the multiplicative faults, denoting torque gain parameter faults of flywheels, are estimated by multiplicative fault estimator and the estimated fault parameters are used for dynamic torque command distribution of flywheels. The final simulation examples and performance comparison of three fault-tolerant schemes show that the proposed scheme based on fault effect classification is an effective, flexible and saving-energy fault-tolerant satellite attitude control scheme. It possesses an engineering value for improving reliability and prolonging on-orbit working lifetime of satellites.