Experimental assessment of wind gust effect on PVTOL aerial vehicles using a wind tunnel

The use of low scale unmanned aerial vehicles (UAV) for various applications has been steadily increasing in the last years. As with any other aircraft, care should be taken in the design process in order to comply with airworthiness and safety requirements. In particular, the effect of wind gusts on these vehicles can lead to loss of maneuverability, control and system failure. It is shown that wind gusts are difficult to model and analyze theoretically. On the other hand, the use of wind tunnels allows testing the vehicles under controlled conditions, which in turn allows for general conclusions to be drawn. In this article, the problem of assessing wind gust effects on typical low scale UAV control systems is tackled via wind tunnel testing. In particular, the control of the roll angle of a translation-limited planar vertical takeoff and landing (PVTOL) is studied with the aid of a wind tunnel test bench. The results show that the effect of wind gust is significant, highly non-linear and is not limited to one kind of perturbation source. Thus, its effect must not be neglected during the design stage of these vehicles. Notwithstanding the complexity of wind gust, the use of classical frequency-based perturbation rejection tools allows obtaining useful conclusions regarding the nature of wind gust as an input perturbation.