Adaptive Sliding-Mode Anti-Disturbance Attitude Control for UAVs With Actuator Faults and Dead Zones

This paper addresses the problem of adaptive robust attitude control for fixed-wing unmanned aerial vehicles subject to actuator faults, input dead zones, matched disturbances, and mismatched disturbances. An adaptive sliding mode disturbance observer is developed to estimate unknown mismatched disturbances and reduce conservatism in gain selection. Based on the reconstructed mismatched disturbances, a modified sliding surface is constructed, upon which a barrier function-based adaptive sliding mode controller is designed to compensate for lumped matched uncertainties and achieve accurate attitude tracking. A notable feature of the proposed controller is its ability to predefine the convergence neighborhood of the sliding variable while eliminating discontinuous terms, effectively mitigating chattering. Theoretical analysis establishes system stability, and numerical simulations validate the effectiveness of the controller.