Motivation: The last decade has seen a dramatic diffusion of battery-powered rotary-wing micro Unmanned Aerial Vehicles (UAVs, a.k.a. MAVs). Their low price, maneuverability and small launch-and-landing footprint has made them extremely popular, but their aerodynamics have disadvantages, such as the relatively poor energy efficiency, that divides multi-rotor UAVs from conventional helicopters and fixed-wing aircraft. The poor capacity of existing lithium-ion polymer (LiPo) batteries is another issue, typically limiting the flight endurance to 15 to 30 minutes.

Goal of the Project: In order to address this issue, several works in the literature have tried to improve the mechanical design and the power system of quadrotors, the simplest class of rotary-wing micro UAVs (see e.g. [1]-[3]). Instead of optimizing the physical parameters in this project low-cost off-the-shelf quadrotor platforms will be considered, and the goal will be to design intelligent path-planning strategies to save energy and extend endurance. Indeed, by leveraging the model of the DC motors, Electronic Speed Controller (ESC), and on-board LiPo battery, the objective will be to generate minimum-energy trajectories for a quadrotor UAV. In particular, the student will focus on the following two problems:
• Make the computation of the optimal trajectories generated with the approach recently proposed in [4], amenable to a real-time implementation on a resource-constrained aerial robot.
• Experimentally validate the optimal trajectories on a real quadrotor UAV, and quantify energy saving in different flight conditions.
At the end of the project, the possibility to extend the method in [4] to non-conventional aerial platforms such as fully-actuated rotorcraft [5], [6], will be also explored (see e.g., http://homepages.laas.fr/afranchi/robotics/?q=node/294).

[1] "The Triangular Quadrotor: A More Efficient Quadrotor Configuration", S. Driessens, P. Pounds, IEEE Trans. Robot., vol. 31, n. 6, pp. 1517-1526, 2015.
[2] "Energy Management for Indoor Hovering Robots", J.F. Roberts, J.-C. Zufferey, D. Floreano, in Proc. IEEE/RSJ Int. Conf. Intel. Robots Syst., pp. 1242-1247, 2008.
[3] "Power and Endurance Modelling of Battery-Powered Rotorcraft", A. Abdilla, A. Richards, S. Burrow, in Proc. IEEE/RSJ Int. Conf. Intel. Robots Syst., pp. 675-680, 2015.
[4] "Minimum-Energy Path Generation for a Quadrotor UAV", F. Morbidi, R. Cano, D. Lara, in Proc. IEEE Int. Conf. Robot. Autom., pp. 1492-1498, 2016.
[5] "Modeling and Control of FAST-Hex: a Fully–Actuated by Synchronized–Tilting Hexarotor", M. Ryll, D. Bicego, A. Franchi, in 2016 IEEE/RSJ Int. Conf. Intel. Robots Syst., 2016, pp. 1689-1694, Daejeon, South Korea 2016.
[6] "A novel overactuated quadrotor unmanned aerial vehicle: modeling, control, and experimental validation", M. Ryll, H.H. Bülthoff, P. Robuffo Giordano, IEEE Trans. Contr. Syst. Tech. vol. 23, n. 2, pp. 540-556, 2015.