Output feedback control of an underactuated flying inverted pendulum

Abstract

This paper tackles the problem of trajectory tracking control for an inverted pendulum mounted on an underactuated unmanned aerial vehicle, operating under constant external disturbances. To model the pendulum’s dynamics, a linear time-varying (LTV) system is first constructed. Within a stochastic framework, a Kalman filter is applied to this LTV system, shown to be uniformly completely observable, to obtain: estimates of the pendulum’s angular velocity; estimates of the external disturbances; and noise-filtered measurements of the pendulum’s orientation. A backstepping nonlinear controller is then designed, and it is analytically proven that the total error in the closed-loop system remains uniformly ultimately bounded. The effectiveness of the proposed strategy is demonstrated through simulations, with additional experimental results further validating its performance.