Incremental sliding-mode fault-tolerant flight control

Abstract

This paper proposes a novel control framework that combines the recently reformulated incremental nonlinear dynamic inversion with (higher-order) sliding-mode controllers/observers, for generic multi-input/multi-output nonlinear systems, named incremental sliding-mode control. As compared to the widely used approach that designs (higher-order) sliding-mode controllers/observers based on nonlinear dynamic inversion, the proposed incremental framework can further reduce the uncertainties while requiring less model knowledge. Because the uncertainties are reduced in the incremental framework, theoretical analyses demonstrate that the incremental sliding-mode control can passively resist a wider range of perturbations with reduced minimum possible control/observer gains. These merits are validated via numerical simulations for aircraft command tracking problems, in the presence of sudden actuator faults and structural damage.