Robust dynamic surface trajectory tracking control for a quadrotor UAV via extended state observer

TLDR

The paper proposes an extended state observer–based robust dynamic surface controller for quadrotor UAVs to track trajectories under parametric uncertainties and external disturbances. The controller is built by modeling the quadrotor dynamics with lumped disturbances, designing backstepping‑based extended state observers for velocity and disturbance estimation, and applying dynamic surface control to achieve asymptotic tracking while avoiding complexity explosion. Stability analysis confirms ultimate boundedness and arbitrarily small tracking errors, and simulations demonstrate superior tracking accuracy and disturbance rejection compared to existing methods.

Abstract

Summary In this paper, we present an extended state observer–based robust dynamic surface trajectory tracking controller for a quadrotor unmanned aerial vehicle subject to parametric uncertainties and external disturbances. First, the original cascaded dynamics of a quadrotor unmanned aerial vehicle is formulated in a strict form with lumped disturbances to facilitate the backstepping design. Second, based on the separate outer‐ and inner‐loop control methodologies, the extended state observers are constructed to online estimate the unmeasurable velocity states and lumped disturbances existed in translational and rotational dynamics, respectively. Third, to overcome the problem of “explosion of complexity” inherent in backstepping control, the technique of dynamic surface control is utilized for trajectory tracking and attitude stabilization, and with the velocity and disturbance estimates incorporated into the dynamic surface control, a robust dynamic surface flight controller that guarantees asymptotic tracking in the presence of lumped disturbances is synthesized. In addition, the stability analysis is given, showing that the present robust controller can ensure the ultimate boundedness of all signals in the closed‐loop system and make the tracking errors arbitrarily small. Finally, comparisons and extensive simulations under different flight scenarios are performed to validate the effectiveness and superiority of the proposed scheme in accurate tracking performance and enhanced antidisturbance capability.