Novel airplane roll mechanism implementation in a wind tunnel

According to recent research conducted by professor Haithem E. Taha and Ahmed M. Hasan, there is a loss in the control capabilities of the ailerons when flying at stall regime. Not only the sensitivity of this control surface decreases in its ability to generate roll moment but it produces the opposite effect, making the aircraft unpredictable. In order to overcome this situation, an unconventional method, called LIBRA, has been devised, involving geometric nonlinear control tools such as Lie brackets. In the numerical simulations, this mechanism would generate up to 4 times more rolling moment than the conventional procedure. The first stage of the experimental research on the LIBRA mechanism consists of finding out the aerodynamic characteristics of a small-scaled aircraft model in which the mechanism will be implemented as well as determining if there really exists a loss in the control capabilities when flying at stall. This experiments will be performed in a wind tunnel and both the forces and moments acting on an aircraft will have to be measured. Currently there exist in the market multi-axis load cells that can measure moments and forces in all directions. However, they have fixed capacities and they are very expensive and delicate. One of the main goals of this thesis will be the design and manufacturing of a modular load cell system able to measure forces and moments in four different axis. Besides, the unconventional method will be thoroughly described from a differential geometry perspective. Finally, by means of the 4-axis load cell system, forces and moments will be measured in different control configurations at stall, in order to test the rolling generating capabilities of the ailerons. Segons un estudi recent dut a terme pel professor Haithem E. Taha i Ahmed M. Hasan, es perd la capacitat de control en els alerons quan l’avió entra en règim de pèrdues. No només la sensibilitat d’aquesta superfície de control decreix en la seva habilitat de generar moment de balanç sinó que a més arriba a produir l’efecte contrari al desitjat, convertint el comportament de l’aeronau en impredictible. Per tal de fer front a aquest problema, un mètode nou, anomenat LIBRA, ha estat ideat, utilitzant eines del control geomètric no lineal com el producte de Lie. En les simulacions numèriques, aquest mecanisme genera fins a 4 cops més moment de balanç que el procediment convencional. La primera fase de la recerca experimental del mètode LIBRA consisteix a trobar