A nonlinear underactuated controller for 3D-trajectory tracking with a miniature helicopter

This work proposes a nonlinear controller for an autonomous helicopter, to track a given 3D trajectory. The starting point is a dynamic model obtained using the Euler-Lagrange formulation, considering the aircraft as a rigid body. The first contribution is the proposal of a suitable control law considering the nonlinear model, with no linearization strategy, and a proof of the stability of the closed-loop system that embeds such controller. The second contribution is the fact that the proposed controller is based on the inverse dynamics, focusing on its underactuated-system character. Finally, simulation results are presented and discussed, which validate the proposed controller.