Innovative Driving Architecture for Unmanned Aerial Vehicles

During the last two decades, Unmanned Aerial Vehicle (UAV) technology has spread quickly to many fields of applications. Wildfire mapping, disaster management but also space exploration are just some of the many fields of application and global awareness about the usage and the power of this device is growing up. One of the biggest issue with a UAV is the battery life especially during a long task where the battery cannot be changed or recharged quickly. For this reason, the efficiency of the powertrain plays an extremely important role to maximize the duration of the battery. Drones roots are back to WorldWar I when many armies tried to develop automatic unmanned planes. After the ’20s, armies of the world’s major powers considered the UAVs as an important tool for the armies and carried out the development of this technology. In the last few years, the fast technological development allowed the UAVs to be used also for a civil purpose. Nowadays the new technologies are boosting up the development of drones from military area to hobbyists. Despite this large diffusion, the literature about drone powertrain is quite poor and the solution used to drive the drone’s motors are the standard solution used in the industrial field. The most important part of the powertrain in a UAV is the Brushless Motor because the efficiency depends on how it is driven. Usually, brushless motors are used for industrial purpose where the efficiency is not so critical and these solutions have been adopted also for UAV. But to increase the flight time it is needed to develop a driving strategy and an hardware architecture designed specifically for UAV. In this thesis, it is studied a way to realize a powertrain architecture to improve the efficiency of the UAV. This thesis, starting from the results obtained in the thesis [6] Modelling, Simulation and Efficiency Analysis of Powertrains for UAV Applications analyze all the possible control and hardware solution to match the results obtained in the previous analysis. In particular, a low weight DC to DC converter is designed and tested to fit all the requirements for an Unmanned Aerial Vehicles and to find a solution that could be applied to existing quadcopters maintaining the same controller. The target of this thesis is to validate the model and to realize an architecture that is more efficient than the traditional one for all power and torque condition. In particular, for the hovering condition, that is the longer condition on a flight, an increment in the efficiency of at least 5 % for each motor must be achieved. This means that in a quadcopter the total battery life would be extended by 20 %.