Sliding fractional order trajectory and attitude control of a quadrotor transporting cable-suspended unknown payloads

Abstract

This article designs a control system for the trajectory tracking problem of a quadrotor vehicle with an unknown suspended load. The presence of this unknown load considerably increases the complexity of the problem while its oscillation acts as an unknown perturbation that affects the dynamics of the vehicle. In this way, the overall trajectory of the quadrotor can be greatly affected despite the existence of a nominal controller for it. This article proposes the design of a fractional order sliding mode control for the solution of this problem. Along with the design of the control law, the stability proof of the closed-loop system is carried out by using the Lyapunov method for fractional systems. The performance obtained by the proposed controller is compared with the classic sliding mode control, observing that the proposed controller significantly improves the results.