Generation of time optimal trajectories of an autonomous airship
Résumé
The natural wind proved itself to be a major parameter to successful flights of airships. It mostly affects a trajectory through its speed. In general, the wind speed can be modeled as a sum of two components: a nominal deterministic component (available through meteorological forecasts or measured with a Doppler radar) and a stochastic component, representing deviations from the nominal one [1, 2]. The closed loop controller takes care of the stochastic part considered as perturbations, while the deterministic component is introduced into the motion planner. In general, the optimality of a trajectory can be defined according to several objectives, like minimizing the transfer time or the energy. Traditionally, trajectories are optimized by the application of numerical optimal control methods that are based on the calculus of variations.