The study of the monolithic piezoelectric actuator, the dominant type of micropositioner is an attractive and challenging area, where realtime control theory and digital signal processing are effectively applied. The actuator can be applied in precision instruments and precision control, such as microscopes, medical and optics instruments because of the piezoelectric ceramic's high resolution, fast transient response, and potential low cost. However, hysteresis nonlinearity and lightly damped vibration exist in the system, which limit the actuator applications.

This work focuses on the hysteresis characteristics in time and frequency domains along with experimental and simulated results to verify the effectiveness of the model in describing the hysteresis phenomena. The analytic expressions of the hysteresis harmonics are further applied in hysteresis parameter estimation.

A reduced order nonlinear hysteresis observer compensator is proposed, and the stability of the compensated system is discussed. The compensator reduces the hysteresis effect significantly under simulated and experimental conditions. Furthermore, an adaptive hysteresis observer compensator is further presented to compensate the slowly changed hysteresis parameters. Time division multi-control strategy is proposed to implement fast transient response, low vibration and high resolution.

Extensive numerical simulation and real-time experiment are carried out to verify the control strategies. GUI is developed to implement the communication between the code in DSP memory and Labview, which improves the efficiency in system test.