Powertrain Design for Hand-Launchable Long Endurance Unmanned Aerial Vehicles

This paper describes methods for design of a hand-launchable, back-packable unmanned aerial vehicle for long endurance flight. The proposed design methods involve the development of empirical and physics-based contributing analyses to model the performance of the aircraft subsystems. The contributing analyses are collected into a design structure matrix which is used to map aircraft performance metrics as a function of design variables over a defined design space. The results of the design process are used to construct a demonstration hand-launchable, back-packable aircraft. Test results from the demonstration aircraft and its subsystems are compared to predicted results to validate the contributing analyses and improve their accuracy in further design iterations. Nomenclature g = acceleration due to gravity ρ = air density A = wing area c = chord length CD = coefficient of drag CL = coefficient of lift FD = drag force FL = lift force Fx = force component in x direction Fy = force component in y direction P = cruise power θ = trajectory angle θ0 = launch angle ax = acceleration component in the x direction ay = acceleration component in the y direction vstall = stall velocity v0 = launch velocity vx = velocity component in the x direction vy = velocity component in the y direction xi = displacement in the x direction yi = displacement in the y direction ma = aircraft mass mm = motor mass mb = battery mass d = propeller diameter p = propeller pitch Nb = number of propeller blades Q = propeller torque index = motor identifier I0 = no load motor curren