Full attitude tracking control of a tiltrotor UAV on SO(3)

Abstract

This paper presents novel results for the attitude tracking control of a tiltrotor unmanned aerial vehicle (UAV). This kind of UAV has two tiltable rotors while both thrust force and thrust direction can be controlled, and thus has four input degrees of freedom. A nonlinear dynamic model defined on SO(3) is proposed and analysed. An attitude tracking controller is developed using Lie Group and Lie Algebra theory, achieving smooth attitude tracking and avoiding the singularity problem of Euler Angles. Numerical simulation shows the controller has desirable closed loop performance and global asymptotic stability.