Maximum-system-reliability control allocation for spacecraft with redundant actuators

On-orbit useful lifetime is a critical metric for spacecraft missions, for which we propose a maximum-system-reliability control allocation scheme for spacecraft with redundant actuators. The dynamic reliability model for the redundant actuator system is formulated, incorporating an online parameter estimation method initialized with offline estimates. On this basis, we define a control allocation optimization problem that maximizes the one-step system reliability prediction. To enable efficient online computation, a recursive optimization algorithm is introduced. Theoretical analysis proves that the proposed approach can extend the useful lifetime of the redundant actuator system with any failure mode. A comparative example of spacecraft attitude stabilization validates the feasibility, generality, and superiority of the proposed method.