Two Seconds to Touchdown - Vision-Based Controlled Forced Landing

The use of UAVs in civilian and domestic applications is highly demanding, requiring a high-level of capability from the vehicles. This work addresses the task in which a UAV is performing an inspection on a set of power lines and an emergency situation occurs requiring the UAV to avoid the lines and then find a safe landing area (a forced landing). This problem is approached using vision, where the vision system acts as the overall controller sending velocity commands to a low-level controller. The use of vision here allows the 2D position of the UAV to be updated by an image-based signal where the error to minimize is the location of a feature or set of features in the image. The system has been tested in a air vehicle simulator (AVS) - a cable array robot which allows to simulate and control three DOF (translation) of a UAV. Results obtained from tests in a scale scenario show the feasibility of this approach