Metodologie e tecniche di guida e controllo durante le fasi di approccio ed atterraggio: il sistema di navigazione e il problema della stima ottima di stato

This project is relevant to techniques for Altimetry Systems For Autonomous Landing and Take Off that has been performed in the framework of the technology studies for the Italian government research program PRORA-UAV owned by the Italian Aerospace Research Center (CIRA). The project deals with integration of advanced altimeters onboard Unmanned Aerial Vehicles (UAVs) to be used as vertical navigation sensors for autonomous take off and landing on runways that are not equipped with navigation aids. Landing is a very demanding phase in terms of vertical navigation for both manned and unmanned aircrafts. Indeed, the standalone GPS civil service is not capable to guarantee these performances. As a consequence, more accurate altimeters are investigated to be adopted onboard. All these sensors need to meet power and mass requirements for a small UAV. Well-suited altimetry determination techniques have been investigated and an error budget analysis has been performed to determine the expected accuracy level. This analysis accounted for range, attitude, and mounting errors influence on altitude measurement. Finally, a specific sensor fusion algorithm has been developed in order to obtain the best state estimation taking advantage of measurements from standard navigation sensors such as GPS and inertial sensors.