Modeling and Unilateral Adaptive Control of a Flexible Slung Load System for Multirotor AAV With Actuator Constraints and Faults

This study investigates the modeling and unilateral adaptive control of the flexible slung load system (FSLS) of a full-state multirotor unmanned aerial vehicle (UAV) subject to actuator constraints and faults. A three-dimensional full-state dynamic model for the multirotor UAV FSLS is established utilizing the extended Hamilton principle. Previous studies have considered the neural network approximation method to investigate the coupling effects of actuator constraints and faults; however, this method may create an algebraic loop. To circumvent this issue, a compensation strategy is proposed to handle the coupling problem of actuator constraints and faults via hyperbolic tangent functions, Nussbaum -type functions, and an inverse compensation mechanism. Based on the proposed compensation strategy, a unilateral adaptive boundary control relation is designed to restrain the vibration in a dynamic model of a three-dimensional multirotor UAV FSLS with actuator constraints and faults via the backstepping method. The convergence of the closed-loop system for the multirotor UAV FSLS is analyzed using the Lyapunov technique. The effectiveness of the proposed control algorithm is validated using numerical simulations.