Fixed-time prescribed performance formation control of heterogeneous UAV-USV systems under actuator faults

This paper addresses the robust cooperative control problem of heterogeneous unmanned aerial vehicles (UAVs) and unmanned surface vehicles (USVs) under actuator faults and complex environmental disturbances. A heterogeneous fixed-time prescribed performance formation control framework is proposed to ensure precise coordination among the vehicles. Specifically, a disturbance observer-based fixed-time control law is developed for USV formation control, employing a leader-follower topology. Simultaneously, a fixed-time prescribed performance control strategy based on error transformation is designed for the UAVs to ensure convergence within specified performance boundaries. To enhance system resilience, a disturbance observer is designed for the USV formation system to handle complex marine environmental disturbances. Meanwhile, for the UAV subsystem, an adaptive fault-tolerant mechanism is integrated to estimate and compensate for loss of actuator efficiency and bias faults. Lyapunov stability analysis theoretically proves that all tracking errors in the closed-loop system converge to a small neighborhood of the origin within a fixed time, independent of the initial system states. The simulation results validate the effectiveness of the proposed formation methods.