Abstract: Voltage control is by far the most common strategy for driving piezoelectric actuators, but it is, at times, handicapped by large, inefficient amplifiers and nonlinear piezoelectric actuator behavior. Optimizing voltage-feedback amplifiers for driving capacitive-type loads with amplifier schemes such as pulse-width-modulation promises to drastically reduce amplifier weight and improve efficiency. This development work is currently in progress and is discussed in this paper. Also presented are some methods that take advantage of direct charge control of piezoelectric actuators. Direct charge control removes much of the hysteresis that is inherent in voltage control so it is a likely option if a high level of positioning accuracy is needed in a given application. Unlike voltage-feedback control, charge amplifiers can accurately control a piezoactuator open loop. The main drawback to charge control is that periodic removal of charge bias is necessary to prevent actuator drift. Discussed are strategies that attempt to accomplish charge control while simultaneously avoiding actuator drift and conserving power. !3
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