A dynamic creep model of the stack piezo-actuator

There are two classical models, the LTI and the log-type, to deal with the creep effect of the stack piezo-actuator. However, they are static and both have a parameter need to be decided by personal experience. In this paper, an inversely proportional function with no subjective parameters is proposed to model the dynamic creep effect of the stack piezo-actuator. A series of experiments are designed to demonstrate the validity of the proposed model. The results show that the simulation curves are well matched to the experimental data. The maximum sum of squared tracking error (0.1385) of inversely proportional function is lower than that (0.1412) of the LTI model with three first-order modules and that (0.2627) of the log-type model.