High-Rate, High-Precision Wing Twist Actuation for Drone, Missile, and Munition Flight Control

Abstract

This paper covers a new actuation and deflection controller configuration for high-aspect-ratio wings used on subsonic drones, missiles, and munitions. Current approaches to the flight control of these aircraft have unearthed challenges with friction, stiction, slop, bandwidth, and thick boundary layer nonlinearities, which degrade flight control accuracy—especially in terminal flight phases. The approach described in this paper uses directionally attached piezoelectric (DAP) actuators to actively twist a high-aspect-ratio wing for flight control. The DAP actuators were modeled analytically and computationally using linear finite element modeling. A 3″ (7.62 cm) chord × 15″ (38.1 cm) semispan rectangular wing with an NACA 0012 profile was built and structurally tested, demonstrating excellent agreement between theory and experiment. New actuation methods were used to overdrive the PZT-5H piezoelectric elements deep into the repoling range. This overdrive actuation rejuvenated the actuator elements and allowed for dramatically improved deflections with respect to configurations in previous years. Static testing demonstrated deflections in excess of ±1.6° in root-to-tip twist. Dynamic testing showed corner frequencies greater than 310 Hz. A series of wind tunnel tests at up to 180 ft/s (55 m/s, 123 mph, 107 kts, 198 kph) demonstrated excellent roll control authority, rapid manipulation of Clδ, and lift manipulation using quasi-static deflections. The paper concludes with a summary of implications for terminal guidance for drone, missile, and munition flight control in real atmospheres.