Finite-Time Fast Adaptive Backstepping Attitude Control for Aerial Manipulators Based on Variable Coupling Disturbance Compensation
Hai Li, Zhan Li, Fulin Song, Xinghu Yu, Xuebo Yang, Juan J. Rodríguez-Andina
Abstract
Rapid convergence and strong immunity of attitude control under the influence of internal and external disturbances are crucial for aerial manipulators in aerial work tasks. In this article, a practical finite-time fast adaptive backstepping (FAB) attitude control method based on variable coupling disturbance (VCD) compensation is proposed for aerial manipulators to achieve this goal. Unlike traditional coupling disturbance compensation, which only considers manipulator motion, a novel VCD feedforward compensator is proposed that considers motion of both manipulator and load on the end effector. In this way, accurate and timely compensation of strong VCD can be achieved in tasks such as aerial pick and place. In addition, a new fast command filtered adaptive law is proposed to achieve direct estimation and compensation for lumped disturbances stemming from unmodeled dynamics, uncertainties, and external factors. Moreover, the FAB controller and fast command filtered adaptive law are designed with practical finite-time Lyapunov stability, which ensures finite-time stability of system tracking and adaptive law estimation errors with convergence rate faster than exponential. Experimental results are presented and discussed to demonstrate the effectiveness and advantages of the proposed control strategy.