Design, fabrication, and testing of a new twist-active wing design

This paper outlines the design, fabrication and testing techniques used for a new class of active wings. In support of recent efforts to shrink high authority, high speed aircraft flight controls for Micro Aerial Vehicles (MAVs), a new wing design was conceived. Quasi-vortex lattice methods were used to determine roll control power of unswept wings with (1) conventional ailerons, (2) active twist, and (3) a new method which employs root twist only. It was shown that linear wing twist provides 3.9 times more roll control than conventional ailerons. Root twist manipulations are shown to provide 1.6 times more control than twist. A comparison of control authority per unit actuator weight also shows that root actuators are more than 20% lighter than the other two systems. To drive the new root pitch actuator, a directionally attached piezoelectric (DAP) torque-late actuator was built. A laminated plate theory analysis of the 4' span, 3' chord DAP torque-plate showed good correlation between theory and experiment. The DAP torque plate was integrated into a 30' span, 4' chord graphite-epoxy wing. Structural testing showed wing pitch deflections up to +/- 1.5 degree(s) at rates in excess of 70 Hz. Wind tunnel tests were conducted between 1 and 20 ft/s (typical MAV flight speeds) and showed rolling moment coefficients up to +/- 0.026 (equivalent to +/- 8.4 degree(s) of aileron deflection), indicating that the new wing is well suited to flight control of micro-sized aircraft.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.