A novel unmanned aircraft with solid-state control surfaces: Analysis and flight demonstration

Abstract

This article presents a completely servo-less, piezoelectric controlled, wind tunnel and flight tested, remotely piloted aircraft that has been developed by the 2010 Virginia Tech Wing Morphing Design Team (a senior design project between the Departments of Mechanical Engineering and Aerospace and Ocean Engineering). A type of piezocomposite actuator, the Macro-Fiber Composite, is used for changing the camber of all control surfaces on the aircraft. The aircraft is analyzed theoretically for its aerodynamic characteristics to aid the design of the piezoelectric control surfaces. A vortex lattice analysis complemented the database of aerodynamic derivatives used to analyze control response. Steady-state roll rates were measured in a wind tunnel and were compared to a similar aircraft with servomotor actuated control surfaces. The theoretical analysis and wind tunnel testing demonstrated the stability and control authority of the concept, culminating in the first flight of the completely Macro-Fiber Composite controlled aircraft on 29 April 2010. An electric motor-driven propulsion system is used to generate thrust, and all systems are powered with a single lithium polymer battery. This vehicle became the first completely Macro-Fiber Composite controlled, flight tested aircraft. It is also known to be the first fully solid-state piezoelectric material controlled, nontethered, flight tested fixed-wing aircraft.

Experimental testing of spanwise morphing trailing edge concept

“…Leveraging experience with MFCs, the Virginia Tech senior design team created an all-morphing control surface aircraft, shown in Figure 3 [17]. The trailing edge control surfaces of the aircraft were constructed using flat MFC bimorphs with steel substrate, actuating in bending.…”

“…Using a TREK 2220 High Voltage Amplifier as well as the solid-state electrical voltage divider circuit developed by Bilgen et. al , the flexure box design was actuated [17]. A Keyence LKG-402 laser displacement sensor was used to track the displacement of the aileron at 298 mm chord.…”

Low Reynolds Number Behavior of a Solid-State Piezocomposite Variable-Camber Wing

“…Adequate roll control authority was demonstrated in the wind tunnel as well as in flight. In 2010, Butt et al [10] and Bilgen et al [11] developed a completely servo-less, wind-tunnel and flight tested, remotely piloted aircraft. This vehicle became the first fully solid-state piezoelectric material controlled, non-tethered, flight tested fixed-wing aircraft.…”

The design and flight test of a new smart wing system

“…[3][4][5][6][7][8][9] Perhaps the main reasons are the material with high cost and complicated equip ment with high weight. 10,11 But the author believes that smart wing system which can change its shape and style is the trend of future aircraft design.…”