Stability Analysis of a Vision-Based UAV ControllerAn Application to Autonomous Road Following Missions

The stability analysis of a vision-based control strategy for a quad rotorcraft UAV is addressed. In the present application, the imaging sensing system provides the required states for performing autonomous navigation missions, however, it introduces latencies and time-delays from the time of capture to the time when measurements are available. To overcome this issue, a hierarchical controller is designed considering a time-scale separation between fast and slow dynamics. The dynamics of the fast-time system are stabilized using classical proportional derivative controllers. Additionally, delay frequency and time domain techniques are explored to design a controller for the slow-time system. Simulations and experimental results consisting on a vision-based road following task are presented.