Prescribed-time tracking control for a QUAV with a cable-suspended payload and asymmetric partial time-interval output constraints

Abstract

In this article, a prescribed-time observer-based sliding mode tracking control strategy is put forward for a quadrotor unmanned aerial vehicle (QUAV) carrying a cable-suspended payload, which also ensures that the payload is driven to desired trajectories under asymmetric partial time-interval output constraints (APTIOCs). Firstly, to deal with the influence of unknown perturbations rapidly, a prescribed-time disturbance observer is designed. Also, the reachability of the constructed novel nonsingular sliding surface is actualized in an assigned time by employing a prescribed-time sliding mode controller synthesis, from which tracking errors can converge to zero in a predefined time then. It is noteworthy that the proposed APTIOCs are more general than conventional continuous output constraints, which are discontinuous and have limited duration, meaning that they occur only in a specific time period. The salient advantage of APTIOCs lies in its applicability to both continuous constrained case and constraint-free one, without revising the control structure. At last, the effectiveness of the raised control algorithm is demonstrated through simulation experiment.