Adaptive practical output tracking of stack piezo-actuators with coupling hysteresis for dynamic loading applications

The piezoelectric stack actuators (PEAs), being limited to unknown hysteresis, present undesired accuracy. However, experiments show that the effect of dynamic load and the rate of excitation voltage can also cause inclination in hysteresis loop and deteriorate tracking performance. By taking into account the two factors, we propose a coupling hysteresis model based on the modified Prandtl-Ishlinskii operator to estimate the hysteresis nonlinearity in PEAs. When the bounds of system parameters and reference signal are unknown, we develop an adaptive control technique to solve the problem of practical output tracking of PEAs preceded by a non-measureable coupling hysteresis. The method employs the ideas of adding a power integrator technique and universal control, and combines with the proposed coupling hysteresis model without constructing a hysteresis inverse. Simulations demonstrate the efficacy of this adaptive control strategy.