Computational Aspects of Optimization-Based Path Following of an Unmanned Helicopter

This paper considers the path following of unmanned helicopters based on dynamic optimization. We assume that the helicopter is equipped with a flight control system that provides an approximation of its closed-loop dynamics. The task at hand is to compute inputs for this flight control system in order to track a geometrically specified path. A concise problem formulation and a discussion of an efficient implementation are presented. The implementation achieves computation times below the flight duration of the path by exploiting differential flatness properties of parts of the dynamics. Finally, we present quantitative results with respect to convergence and required iterations for a challenging nonlinear path. We show that the proposed optimization based approach is capable of tackling nonlinear path following for unmanned helicopters in an efficient and practicable manner.