Flapping Wing Technology for Micro Air Vehicles Incorporating a Lead Zirconate Titanate (PZT) Bimorph Actuator.

摘要

Army operations have placed a high premium on reconnaissance missions for unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs) (15 cm or less in dimension and less than 20 g in mass). One approach for accomplishing this mission is to develop a biologically inspired flapping wing insect-sized device that can maneuver into confined areas. Analysis of insect flight indicates that in addition to the bending excitation (flapping), simultaneous excitation of the twisting degree of freedom (pitching) is required to adequately control the vehicle. Traditionally, bimorph piezoelectric lead zirconate titanate (PZT) (Pb(Zr0.55Ti0.45)O3) actuators have been used to excite the bending degree of freedom. In laminated or layered structures, bend-twist coupling is governed by having at least one anisotropic layer not aligned with the primary plate axes. By adding a layer of off-axis PZT segments to a PZT bimorph actuator, a functionally modified bimorph now offers a bend-twist coupling, flexural response in the traditional bimorph actuator. This study presents an experimental investigation of both traditional bimorph and functionally modified PZT bimorph designs intended for active bend- twist actuation of cm-scale flapping wing devices. Results are shown comparing aerodynamic parameters for three wing shapes and two PZT designs.