Output feedback second order sliding mode control design for a 3-DOF helicopter based on its simplified model

This paper presents the solution to the tracking control problem for an underactuated scaled autonomous helicopter using variable structure control via output measurements. First, it is designed a state-feedback second order sliding mode controller to stabilize height and rotation positions. Controller is designed from a reduced model of the helicopter and the resulting control law is tested in its full model thus showing the robustness against unmodelled dynamics. Simulation results illustrate the performance the effectiveness of the controller.