Adaptive Predefined-Time Attitude Tracking Control for Quadrotor Using a Novel Terminal Sliding Mode Approach

This paper proposes an adaptive predefined-time terminal sliding mode control (APTSMC) scheme for attitude tracking control of a quadrotor. To create this, an adaptive predefined-time stability controller based on a terminal sliding mode is constructed. The upper bound of convergence time in the proposed scheme can be adjusted by the explicit parameters during the design process of the controller. In addition, it is proved that the attitude tracking error will converge within two periods of the preset time. These two periods are set between two ranges: From the initial values to the sliding mode surface and from the sliding mode surface to the region near the origin. Furthermore, an adaptive law is adopted to eliminate unknown external disturbances and the effects of the uncertainties in the quadrotor model, so it is unnecessary to require the prior knowledge of the upper bound of the perturbations. Simulation results are produced and comparative case studies are carried out to demonstrate that the proposed scheme has faster convergence speed and smaller tracking errors.