Longitudinal and lateral adaptive flight control design for an unmanned helicopter with coaxial rotor and ducted fan

In this paper, Lyapunov-based adaptive attitude control and adaptive longitudinal displacement control methods are designed and implemented for a prototype unmanned helicopter with coaxial rotor and ducted fan configuration. The prototype has longitudinal and lateral symmetry with strong coupling between longitudinal and lateral channels and weak coupling between altitude-heading and longitudinal-lateral channels. Attitude and longitudinal reference models are designed with longitudinal and lateral channel properly decoupled. Real time near-ground flight test results show that longitudinal displacement tracking error is minimum, and the prototype achieves good performance in adaptive decoupling and tracking control as flight speed changes smoothly.