Optic Flow Based Collision Avoidance on a Hybrid MAV

Recent terrorist attacks on the United States have exposed the need for better surveillance and situational awareness technologies. Organizations created to address these needs are aggressively funding research in the use of Micro Air Vehicles for homeland security missions. Such missions have been occurring in caves, tunnels, and urban areas. By mimicking flying insects which navigate in these complex environments regularly, an optic flow collision avoidance system for a MAV was prototyped. However, there were certain instances (e.g. flying directly into a corner) where this system failed. To address this, a new MAV platform was prototyped which enabled a quick transition from cruise flight into a hovering mode in order to avoid such a collision. The hybrid MAV offers the endurance superiority of fixed-wing aircraft along with hovering capabilities of rotorcraft. This paper details the applications and design of a hybrid MAV in conjunction with sensing and control techniques to perform autonomous hovering and collision avoidance. This is, to the best of our knowledge, the first documented success of hovering a fixed-wing MAV autonomously.