POWER MANAGEMENT FOR LANDING UNMANNED AERIAL VEHICLES WITH VERTICAL-LIFT ROTORS

In an example, an unmanned aerial vehicle (UAV) is disclosed, which includes an avionics system, a propulsion system, vertical-lift rotors, and a controller. The controller performs operations including, in response to detecting loss of operation of the propulsion system, determining energy and time constraints based on (i) a remaining avionics battery life and (ii) a remaining rotor battery life. The operations also include using a rotor edgewise inflow model stored on the controller, evaluate parameters for a glide descent trajectory and subsequent rotor-powered flight trajectory to a candidate landing site, to determine whether, based on evaluation of the parameters, an estimated energy consumption during the rotor-powered flight trajectory and time needed for the UAV to land at the candidate landing site exceed the constraints. The operations also include in response to determining that the estimated energy consumption and time needed exceed the energy and time constraints, selecting an alternative candidate landing site.