Rotorcraft path following control for extended flight envelope coverage

This paper addresses the problem of steering a quadrotor vehicle along a predefined path. The problem is formulated so as to dynamically prescribe an adequate time evolution along the path and simultaneously bound the effect of position errors on the actuation. The proposed solution consists of a nonlinear state feedback controller for thrust and torque actuations combined with a path following timing law that i) guarantees global asymptotic convergence of the path following error to zero, for a large class of three-dimensional paths, ii) ensures that the actuation does not grow unbounded as function of the position errors, and iii) allows for zero thrust actuation to be applied when the vehicle is converging to the path. Simulation results are presented to assess the performance of the proposed controller.