Nonlinear and adaptive control design of a helicopter in vertical flight

In this paper, an adaptive backstepping design scheme with sliding mode concept has been developed for the tracking control of a helicopter in vertical flight system. In general, the control of small-scale helicopter is a difficult task, because the helicopter system is highly nonlinear, coupled and sensitive. For simplicity, only vertical flight motion is focused on here. This type of system has only two degrees of freedom, including helicopter altitude and collective pitch angle of blade. The main control objective is not only to track the reference altitude as fast as possible, but also to force the collective pitch angle of blade to converge to the desired angle. The proposed controller has the ability to stabilized the system and reach our control objective successfully. Finally, some simulations are given to illustrate the excellent performance of the proposed control design applied to the helicopter system in vertical flight