Advanced control techniques for post-buckled precompressed (PBP) flight control actuators

Abstract

The dynamic response of a new class of flight control actuators that rely on post-buckled precompressed (PBP) piezoelectric elements is investigated. While past research has proven that PBP actuators are capable of generating deflections three times higher than conventional bimorph actuators, this paper quantifies the work output and power consumption under various axial loads, at various frequencies. An analytical model is presented that supports the experimental findings regarding the increasing work output and natural frequency shift under increasing axial loads. Furthermore, increasing axial loads shows an increase in open-loop piezoelectric hysteresis, resulting in an increasing phase lag in actuator response. Current measurements show an electromechanical coupling that leads to power peaks around the natural frequency. Increasing axial loads has no effect on the power consumption, while increasing the work output by a factor of three, which implies a significant increase in work density over the piezoelectric material itself.