Designing embedded systems for fixed-wing UAVs: Dynamic models study for the choice of an emulation vehicle

Fixed-wing Unmanned Aerial Vehicles (UAVs) are a special class of UAVs which present many advantages notably long range of action. Whereas, design of this kind of UAVs requires heavy logistics like outdoor tests, runways, and experimented pilots. These constraints reverberate on the design of embedded systems for fixed-wing UAVs. Because static tests are not representative, this paper proposes a practical approach to evaluate an embedded system on an appropriate vehicle emulating the dynamic model of a fixed-wing aircraft. For that, a comparison between the dynamic model of fixed-wing aircraft, tank-type mobile robot, and a bicycle is achieved. We show that, contrary to trend in literature, a mobile robot is not the optimal choice to emulate a fixed-wing UAV. Indeed, supposing a motion without slip (and a constant altitude for the aircraft), translation models of the three vehicles are under the form of Dubin car model. Whereas, translation and rotation velocities of tank-type mobile robot are coupled (while it is not the case for the aircraft where propulsion and turning are actuated separately). This constraint defines an allowed kinematic zone which limits the emulation of a fixed wing airplane. In the other hand, in bicycle model “bank to turn effect” is similar to the one observed in fixed-wing aircraft model. Furthermore, both models are not defined when the translation velocity tends to zero (stalling effect). As a conclusion, we propose to use mobile robot to test the navigation layer, and the bicycle to evaluate the sensor processing layer of an embedded system based fixed-wing UAVs applications.