Entomopter Manoeuvrability Enhancement by Deformations Control of Flexible Flapping Wings

§In the background of preparing this paper lies our believe that transferring ideas from the more matured disciple like aircraft technology to emerging animal technology should be beneficial for the later one and vice-versa. One integrated idea, of special interest to both disciplines, is the active flexible wing concept. This concept represents a return to the Wright Brothers’ idea of wing warping or twisting by combining wing structures and flight controls to perform the desired manoeuvres. It is well known that the dynamics of entomopter over the flight envelope is highly nonlinear. The character of the loads acting on the vehicle particularly the aerodynamics - vary substantially over the angle of attack operating range (which may nowadays include post stall incidences). The control of this type of plant can be achieved adequately via a variety of approaches, provided that the parameters of the controller (the gains in particular) are scheduled with flight condition. The nonlinearity of the system makes it difficult to implement a strategy of interpolating between gains derived from a few choice trim points. This is because the plant and the controller interact such that it is not clear precisely what the closed loop trim points are in vide flight regions, because aerodynamic loads often become asymmetric and where inertial coupling is significant. In theis paper we developed aeroelastic analysis for a flexible wing for an imposed harmonic flapping motion about the root chord of the wing. A Matlab code was written based on the analysis. This code was used to find the average lift and thrust of a wing of known aerodynamic and structural properties. The results compared well with the published results.