H_∞ fault-tolerant decentralized observer-based PID team formation tracking design for NCS of large-scale LEO satellites

In this study, a simple decentralized H$$ _{\infty} $$ fault-tolerant observer-based proportional-integral-derivative formation tracking design is proposed for network control systems of large-scale low earth orbit satellites under external disturbance, coupling and malicious attack signals via wireless communication channels. First, a novel reference-based feedforward linearization control scheme is introduced, transforming the nonlinear formation output feedback tracking control problem into an equivalent linearized formation tracking control system of each satellite. To prevent faults from corrupting the estimation and control of the satellite formation, two novel smoothing models of actuator and sensor fault signals are embedded in the equivalent linearized formation system of each satellite. Then, a decentralized H$$ _{\infty} $$ fault-tolerant observer-based proportional-integral-derivative control strategy is proposed to efficiently attenuate the effect of actuator and sensor faults, measurement noise and satellite coupling on the overall team formation. We only need to solve a linear matrix inequality-constrained optimization problem for each satellite to achieve the optimal H$$ _{\infty} $$ formation problem. Finally, a team formation example with twelve satellites crossing four orbits for a specific mission is provided to validate the proposed design, comparing it with other methods.