U.S. Army - Augmented Actuation Devices for Adaptive Structures

Techno-Sciences, Inc. (TSi), in collaboration with the Smart Structures Laboratory of the Alfred Gessow Rotorcraft Center at the University of Maryland, are developing an innovative Active Pitch Link (APL) Technology for improved helicopter rotor performance. The APL exploits the beneficial performance characteristics of a new magnetostrictive material, GalFeNOL and nano-particle Magnetorheological (MR) fluid technology.

This hybrid device efficiently marries two high-energy density electromechanical materials to provide full-scale rotor control and can be retrofit to existing rotor systems and powered by existing rotor blade de-icing equipment. The control authority and bandwidth capability of the APL technology is expected to provide the full range of rotor control, encompassing primary flight control, Higher Harmonic Control (HHC) for vibration reduction and noise mitigation, and other extreme flight loads reduction.

Central to the our smart rotor concept is the configuration of the adaptive material as a discrete component that does not require on-blade installation. In contrast to embedded and/or flap actuation devices, the APL system does not require modification to existing rotor blade production practices.

Our APL technology will significantly improve military and commercial rotorcraft systems by improving the rotor performance over a wide range of flight conditions. Specific enhancements include elimination of the swashplate, reductions of rotor vibration and noise, and improved low-speed transition flight performance for Nap-of-the-earth (NOE) operations, among others. From an operational perspective, the reduced complexity of the smart APL rotor will considerably minimize rotorcraft maintenance costs.

The APL technology is applicable to a wide range of end-users in the Defense, commercial, and industry sectors. The low-cost, retrofit capable APL system is particularly attractive for high-performance aircraft, UAV, missile systems, spacecraft, adaptive optics, and other applications where high bandwidth, large displacement, and high actuation forces are required in an energy efficient and compact package. In summary, the key benefits and payoffs of the APL technology are as follows:

• The first application of GalFeNOL to structural control
• Advanced fluid models enable design for high power output
• First application of nano-particle MR fluids in a rotating environment
• Use of nano-fluid MR fluids to achieve control without moving components
• Revolutionary rotor hub design, eliminating conventional swashplate and hydraulic actuators
• Combine primary flight control with active vibration control; applications beyond rotary wing