Dynamics and Performance of Tailless Micro Aerial Vehicle with Flexible Articulated Wings

Abstract

The purpose of this paper is to analyze and discuss the performance and stability of a tailless micro aerial vehicle with flexible articulated wings. The dihedral angles can be varied symmetrically on both wings to control the aircraft speed independently of the angle of attack and flight-path angle, while an asymmetric dihedral setting can be used to control yaw in the absence of a vertical tail. A nonlinear aeroelastic model is derived, and it is used to study the steadystate performance and flight stability of the micro aerial vehicle. The concept of the effective dihedral is introduced, which allows for a unified treatment of rigid and flexible wing aircraft. It also identifies the amount of elasticity that is necessary to obtain tangible performance benefits over a rigid wing. The feasibility of using axial tension to stiffen the wing is discussed, and, at least in the context of a linear model, it is shown that adding axial tension is effective but undesirable. The turning performance of an micro aerial vehicle with flexible wings is compared to an otherwise identical micro aerial vehicle with rigid wings. The wing dihedral alone can be varied asymmetrically to perform rapid turns and regulate sideslip. The maximum attainable turn rate for a given elevator setting, however, does not increase unless antisymmetric wing twisting is employed.

A Flight Mechanics-Centric Review of Bird-Scale Flapping Flight

“…The reader is referred to [17] for a complete derivation, and to [16] for a derivation of the equations of motion of an aircraft with flexible flapping wings. The equations presented in this section have been borrowed from [17].…”

“…It was shown by Paranjape and coauthors [16] that flexibility does not necessarily bring about a significant improvement in the performance, and can in fact degrade certain metrics such as the coordinated (zero sideslip) turn rate by reducing the trim speed for a given tail setting. Moreover, unless the wing is highly flexible, there is no qualitative difference in the stability of rigid and flexible wings.…”

“…For example, Abdulrahim et al [51] optimized the wing twist actuation for a flexible membrane-like wing for achieving a rapid roll rate. Paranjape, Chung and coauthors [16,17] developed an MAV concept which uses the wing dihedral for longitudinal as well as lateral-directional control. The concept shed additional insight into the roles of quarter chord pitching moment and trailing edge flaps in yaw control, and was flight tested successfully [18].…”

“…In [16,17], we developed an articulated wing aircraft which employed the (symmetric and asymmetric) wing dihedral for both longitudinal and lateral control. We also flight-tested the technology, which was the outcome of a first-principle reappraisal of flight mechanics of non-fixed-wing aircraft [18].…”

PDE Boundary Control for Flexible Articulated Aircraft Wings

“…The reader is referred to Ref. [1] for a detailed and more general derivation of the equations of motion.…”