Hysteresis nonlinear modeling and compensation of piezoelectric ceramic sensors in micro measurement systems

The hysteresis nonlinearity of piezoelectric ceramic sensors in micro measurement systems affects detection accuracy. This study analyzes the micro polarization mechanism of piezoelectric ceramics and explains the reason for hysteresis nonlinearity of piezoelectric ceramic sensors. An improved Bouc-Wen (B-W) model, which can reflect the asymmetric hysteresis characteristics of piezoelectric ceramic sensors, is raised to effectively compensate for the hysteresis nonlinearity of piezoelectric ceramic sensors and improve detection accuracy. The influences of model parameters on the size, shape, and asymmetry of the hysteresis curve are studied, and the response characteristics of the model are analyzed when the frequency and amplitude of the input signal are changed. A method for solving the inverse model is provided. The improved B-W inverse model is adopted as a compensator for the hysteresis nonlinearity of piezoelectric ceramic sensors. The results of the experiments show that the established model can describe the hysteresis property of piezoelectric ceramic sensors. After improved B-W hysteresis inverse compensation, the corrected displacement is always able to track the actual input displacement of the sensor, and tracking error of the improved B-W inverse compensation is much smaller than that of the traditional B-W inverse compensation. The detection accuracy of piezoelectric ceramic sensors is effectively ensured.