Switched linear parameter-varying tracking control for quadrotors with large attitude angles and time-varying inertia

This paper is concerned with large-angle attitude tracking control for quadrotors in the presence of time-varying inertia and external disturbances using a switched linear parameter-varying (LPV) system method. The attitude system of the quadrotor is divided into two parts, that is, the outer attitude-angle loop and inner angular-velocity loop. A feedback linearization controller is designed in the outer loop to generate the desired angular velocities. In the inner loop, the nonlinear quadrotor dynamics with time-varying inertia is approximated by a switched LPV system that consists of a series of LPV models. The persistent dwell time (PDT) switching logic is adopted to describe the fast and slow switches coexist among these LPV models. Then, both the continuous-time state-feedback and dynamic output-feedback controllers are designed, which ensure the globally uniformly asymptotically stability and (Formula presented.) external disturbance attenuation performance of the attitude tracking error system. Finally, the effectiveness of the proposed tracking control method of quadrotors is validated with an example.