Flight control of convertible UAV based on extended-state-observer

Focusing on the control system of convertible UAV, which is nonlinear, strongly coupled and uncertain due to its complexity in layout, structure and aerodynamic peculiarity, a kind of control method based on extended-state-observer (ESO) is proposed. First, the dynamic model inversion technique based on reference model tracking is applied to linearize the object and eliminate the coupled factors. Then, the unknown disturbances in the system including un-modeled dynamic performance and inversion error are estimated and compensated by ESO. ESO needs not any information about the object´s mathematic model and has succinct structure, which is quite different from other adaptive control methods. The simulation results show that by this method, the anticipant movement and mode conversion of convertible UAV can be realized properly, and the system has strong robustness.