Control of nonlinear piezoelectric stack using adaptive dither

In this paper, an adaptive dither control is applied to neutralize the multiloop hysteresis commonly found in piezoelectric ceramic based devices. The device being compensated is a lead zirconate, lead-titanate (PZT) stack whereas the hysteresis nonlinearity is described by Dahl's augmented solid friction model, that accounts for both the major, on-axis and the minor, off-axis loops. The notion of "weak scalability" is introduced to facilitate the use of spectral analysis to determine the level of nonlinearity which, in turn, is regulated by the adaptive dither mechanism. Extensive numerical simulation data confirm the effectiveness of the adaptive dither scheme.