Morphing Wing Micro-Air-Vehicles via Macro-Fiber-Composite Actuators

Abstract

*† ‡ § ** The design and implementation of a morphing unmanned aircraft using smart materials is presented. Articulated lifting surfaces and articulated wing sections actuated by servos are difficult to instrument and fabricate in a repeatable fashion on thin, composite wing microair-vehicles. Assembly is complex and time consuming. A type of piezoceramic composite actuator commonly known as Macro Fiber Composite is used for wing morphing. The actuation capability of this actuator on fiberglass unimorph was quantified by experimentation. Wind tunnel tests were performed to compare conventional trailing edge control surface effectiveness to an MFC actuated wing section. The continuous surface of the MFC actuated composite wing produced lower drag and wider actuation bandwidth. The MFC actuators were implemented on a 0.76 m wingspan aircraft. The remotely piloted experimental vehicle was flown using two MFC patches in an elevator/aileron (elevon) configuration. Preliminary testing has proven the stability and control of the design. I. Introduction This study investigates the use of macro fiber composites (MFCs) to control the roll and pitch maneuvers of micro air vehicles (MAVs). Design, manufacturing, and the control of MAVs in unsteady aerodynamic loading remain an active area of interest to researchers. The authors aim to understand the behavior of MFC actuated micro air vehicles under low speed, quasi steady air flow. Wind tunnel tests were conducted to quantify the effectiveness of MFC actuators. Results show that MFC actuation does have improved efficiency over a conventional control surface. The main goal for these experiments was to show the improved performance of a variable camber airfoil compared to a conventional control surface at low Reynolds Numbers. An experimental MAV designed and built by the authors was used as a test platform for the morphing wing concept. This paper first covers the background of the research. The next section presents the wind tunnel experimentation setup and test results. Next, the experimental aircraft design and initial flight results are presented. The paper concludes with a summary of results and discussion of future work.