Modelling of Unmanned Aerial Vehicles with Vertical Take Off and Landing Capabilities

UAVs offer an affordable and sustainable way to improve monitoring of large areas contributing, as example, to gather large amount of data or to improve the surveillance of sites in which criminal activities such as clandestine immigration should harm safety of peoples. Patrolling of large areas involves the use of Unmanned Aerial Vehicles with large autonomies, a feature that is much easier to be obtained with fixed wing planes. Also, VTOL (Vertical Take Off and Landing) features are highly desirable to assure an easy and fast deployment. For these reasons, a hybrid propulsion layout is adopted: wings assure lift for prolonged missions in an efficient way, while multiple rotors with fixed axis are used to assure hovering and VTOL capabilities. So, the superposition of these two propulsion systems assures a relatively simple and robust construction and control of the UAV. However, some further cautions must be taken during the transition from cruise speed to hovering condition and vice versa. For these reasons authors propose in this work a simplified model aiming to simulate the behavior of the UAV to support a better comprehension of involved dynamics and a better design optimization of the system.