Controller's parameters tuning in presence of time-delay measurements: an application to vision-based quad-rotor navigation

The stability analysis of a quad-rotor rotor-craft which uses a combination of imaging, inertial and altitude sensors to measure its states is addressed. A hierarchical controller is designed in two steps. The fast-time scale dynamics are stabilized using classical PD controllers. The slow time-scale dynamics are analyzed with delay frequency and time domain techniques. The proposal is validated by simulation and experimental results, showing the effectiveness of the method.