Hysteresis modeling and analysis of piezoelectric actuators using a modified LuGre model at different preloads and frequencies

Despite a large of models proposed to characterize the nonlinear hysteresis of piezoelectric actuators, few of them can show the effects of different preloads on the nonlinear hysteresis. In this paper, a modified LuGre model (MLM) is presented for piezoelectric actuators under different preloads to accurately characterize its dynamic hysteresis nonlinearity at different frequencies. Based on the classical LuGre model (CLM), the presented model introduces infinite impulse response filters and smoothness coefficient to simplify it. The parameters of the models were identified by the non-linear least squares method. A series of experiments were conducted to verify the validity of the MLM under different preloads at different frequencies excitation signals.In the constant frequency experiments under different preloads, the MLM reduces the mean error by 68.1%−81.9% compared with the CLM; In the constant preload experiments at different frequencies, the MLM reduces the mean error by 72.2%−83.0% and 65.9%−83.2% compared with the classical Bouc–Wen model (CBM) and the CLM.