Implementation of a robust and nonlinear attitude control system for a small-scale unmanned helicopter

A robust and nonlinear attitude control framework for a small-scale unmanned helicopter is presented. The framework contains a sliding mode roll and pitch controller and an extended state observer(ESO). The proposed sliding mode technique is adopted to derive the control law, and the extended state observer is applied to estimate the neglected items and external disturbances. Together with these two approaches, attitude controller is designed to force the actual attitude to converge to the reference signals. Simulation and experiment on a small-scale helicopter are carried out to verify the proposed control scheme.