Dan J. Clingman

High voltage switching piezo drive amplifier

Abstract This paper describes the development and testing of a 3KV, 400 ma piezo drive switching amplifier . This amplifier is used to drive Piezo Fiber Composite (PFC) material imbedded in a 1/6 scale CH-47 blade. This amplifier will allow higher harmonic control of the blade thus reducing rotor craft vibration and noise. The amplifier recycles reactive energy required to drive piezo material allowing for an efficient amplifier design. A multi level topology is used allowing solid state switching devices with voltage rating of half the output drive voltage. The amplifier modular design allows easy migration to the power levels required to drive a full size CH-47 blade. This work was done in conjunction with the Smart Structures for Rotor Craft Control (SSRC) in support of DARPA/AFOSR.

Shape memory actuator systems and the use of thermoelectric modules

Thermally activated shape memory materials have been employed as actuators fora number of years. They are generally activated by electrical resistance heaters, or sometimes by direct electrical resistance. Thermoelectric modules can also provide activation energy, and they provide several unique advantages over the more conventional heating methods. Antagonistic Shape Memory Actuator systems, the utilization of thermoelectric modules as heaters, and the advantages and practical approaches for utilizing actuators employing thermoelectrics are discussed.

High-power piezo drive amplifier for large stack and PFC applications

This paper describes the continuing development of Boeing High Power Piezo Drive Amplifiers. Described is the development and testing of a 1500 Vpp, 8 amp switching amplifier. This amplifier is used to drive a piezo stack driven rotor blade trailing edge flap on a full size helicopter. Also discuss is a switching amplifier designed to drive a Piezo Fiber Composite (PFC) active twist rotor blade. This amplifier was designed to drive the PFC material at 2000 Vpp and 0.5 amps. These amplifiers recycle reactive energy, allowing for a power and weight efficient amplifier design. This work was done in conjunction with the DARPA sponsored Phase II Smart Rotor Blade program and the NASA Langley Research Center sponsored Active Twist Rotor (ATR) blade program.

High-voltage switching piezo drive amplifier

This paper describes the development and testing of a 4KVpp, 750 ma piezo drive switching amplifier. This amplifier is used to drive Piezo Fiber Composite material imbedded in a 1/6 scale CH-47 blade. This amplifier will allow higher harmonic control of the blade thus reducing rotor craft vibration and nose. The amplifier recycles reactive energy required to drive piezo material allowing for an efficient amplifier design. A multi level topology is used allowing solid sates switching devices with voltage rating of half the output drive voltage. The amplifier modular design allows easy migration to the power levels required to drive a full size CH-47 blade. This work was done in conjunction with the Smart Structures for Rotor Craft Control in support of DARPA/ONR.

Mechanical strain energy shuttle for aircraft morphing via wing twist or structural deformation

Direct structural deformation to achieve aerodynamic benefit is difficult because large actuators must supply energy for structural strain and aerodynamic loads. This ppaer presents a mechanism that allows most of the energy required to twist or deform a wing to be stored in descrete springs. When this device is used, only sufficient energy is provided to control the position of the wing. This concept allows lightweight actuators to perform wing twisting and other structural distortions, and it reduces the onboard mass of the wing-twist system. The energy shuttle can be used with any actuator and it has been adapted for used with shape memory alloy, piezoelectric, and electromagnetic actuators.

Shape memory alloy consortium and demonstration

The Shape Memory Alloy (SMA) Consortium (SMAC) has been developing actuators and magnetically actuated SMA materials. This paper will summarize the overall SMAC developments, and concentrate on the development of a SMA torsional actuator. This is being developed for quasi-static twisting the V-22 rotor blades for added performance. The paper provides updated results to the 1999 SPIE paper on this subject, including further and more focused development of the actuator that combines thermoelectric heat control with SMA materials.