A new deformation control approach for flexible wings using moving masses

Abstract

This paper presents a new deformation control concept based on moving mass control technique for the flexible wing of the HALE vehicles. Such mass actuated wings can actively adjust its aeroelastic deformation to avoid the unexpected large deflection and also function as a “seamless morphing wing” to improve flight performance. This investigation focuses on the modeling, analysis, and primary controller design of a high-aspect-ratio wing controlled by an internal moving mass. The equations of motion are derived first by considering the couplings among the structural dynamics, the unsteady aerodynamics, and the transient motion of the mass. The variations in flutter speed and steady-state deformation with the locations of the mass are presented. The time-domain simulations are presented under various travel profiles for the moving mass. The feasibility of using moving mass for deformation control of the flexible wing is primarily proved. Placing the moving mass in front of the elastic axis is preferable to obtain higher flutter speed and larger deformation control authority. Continuous changes in aerodynamic forces can be realized following the structural deformation. The unsteady aerodynamic effect is beneficial for obtaining the moderate deformation control performance without oscillations and also eliminates the complex dynamic nonlinear coupling effects. Finally, a proof-of-concept control system integrated with incremental and positional PD controllers is designed to achieve the desired configuration of the wing.