Piezoelectric Morphing versus Servo-Actuated MAV Control Surfaces

Abstract : A novel morphing control surface design employing piezoelectric Macro Fiber Composite (MFC) actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has revealed several observations. The conformal morphing airfoil geometry increases the lift-to-drag ratio over a servo-actuated flapped airfoil design, showing benefits in aerodynamic efficiency. The embedded MFC actuators eliminate the servo actuator volume from vehicle packaging however, the MFC drive electronics must be taken into consideration. While the weight of the current prototype morphing system exceeds that of a traditional servo and linkage implementation, the weight is comparable and may not be prohibitive for some applications. The comparable power requirement and superior bandwidth make the morphing actuation a feasible and attractive approach for certain air vehicle designs. An order of magnitude increase in bandwidth was observed using the morphing flight control actuation. Ongoing reliability testing of the morphing specimens has demonstrated that solid-state morphing actuation has not failed within 10(exp 5) cycles. Flight tests are planned to fully prove the benefits of the morphing actuation over a servo-actuated design.