3-D Path-Following Control for a Model-Scaled Autonomous Helicopter

A 3-D path-following controller is proposed in this brief for a 6-degrees-of-freedom model-scaled autonomous helicopter. The reference path and path-following errors are newly defined using implicit expressions. On the basis of geometric analysis, a new speed error is designed for singularity avoidance. The proposed control algorithm is designed using command filtered backstepping, such that complicated solutions for derivatives of virtual controls are circumvented. It is proved that, with the proposed controller, path-following errors are locally ultimately bounded. Theoretical results are demonstrated by the numerical simulation.