Antiwindup Finite-Time Attitude Control for a Quadrotor System: Multistage Semiimplicit Euler Implementation

In this work, the multistage semiimplicit Euler digital implementation is proposed for a switched antiwindup super-twisting control (AWSTC) to achieve the precise and robust attitude tracking. The algorithm of AWSTC is designed based on the singular perturbation redesign, where the high gain feedbacks are automatically activated for the global stability of tracking errors in presence of controller saturation. As a result, the attitude tracking performance is significantly improved, even when the initial conditions are far away from the origin. Then, the semiimplicit Euler method of AWSTC is proposed to mix explicit and implicit discretizations for attenuating the undesirable numerical chattering of the explicit Euler methods. In this situation, the selection of a relatively large sampling period is permitted, and thus the overestimation of controller gains for inducing the numerical chattering is also avoided. Both the simulation and experimental results on the quadrotor platform confirm the effectiveness and merits of the proposed algorithm.