Adaptive Control of Aerobatic Quadrotor Maneuvers in the Presence of Propeller-Aerodynamic-Coefficient and Torque-Latency Time-Variations

Abstract

We present a study of the dynamics and control of a 28-gram quadrotor during the execution of aerobatic maneuvers in the presence of propeller-aerodynamic-coefficient and torque-latency time-variations. First, through a momentum-theory-based analysis of the flow field surrounding the robot during aerobatic flight, we develop a dynamic linear time-varying (LTV) description of the torque acting on the flyer in which both considered effects explicitly appear as distinct mathematical terms. Then, an adaptive control scheme, composed of a backstepping controller and a modified recursive least-squares (RLS) estimator, is designed to counteract the negative effects produced by the time-varying dynamics of the torque that drives the flyer. The suitability and efficacy of the proposed methods are demonstrated through real-time flight experiments in which the quadrotor autonomously performs three different types of aerobatic maneuvers: triple flips, Pugachev's Cobras and mixed flips. Furthermore, analyses of the experimental data compellingly show that the proposed control scheme consistently improves the performance of the aerial vehicle during aerobatic flight, compared to those achieved by using a high-performance linear time-invariant (LTI) controller that does not account for time-varying torque generation.