Adaptive Backstepping Control of a 2-DOF Helicopter

This paper proposes an adaptive nonlinear controller for a 2-Degree of Freedom (DOF) helicopter. The proposed controller is designed using backstepping control technique and is used to track the pitch and yaw position references independently. A MIMO nonlinear mathematical model is derived for the 2DOF helicopter based on Euler-Lagrange equations, where the system parameters and the control coefficients are uncertain. Unlike some existing control schemes for the helicopter control, the developed controller does not require the knowledge on the system uncertain parameters. Updating laws are used to estimate the unknown parameters. It is shown that not only the global stability is guaranteed by the proposed controller, but also asymptotic tracking and transient performances are quantified as explicit functions of the design parameters. Simulations and experiments are carried out on the Quanser helicopter to validate the effectiveness, robustness and control capability of the proposed scheme.